Hello again.

Mann vs Machine allows for vast diversity in team composition. In spite of the established Two Cities meta, many team compositions can be successful. However, if you look at the most successful combinations, there is almost always one thing in common: the presence of an Engineer on the team. While most classes can have another class become a suitable replacement, only the Engineer is able to build dispensers, sentries, and teleporters. These buildings become the backbone of a proper defending team. Without them, the missions become noticeably more difficult (or at least inconvenient - usually because of lack of ammo resupply)

At the same time, the engineer can often be seen as a boring class that is necessary "but only for the dispenser". Some experienced MvM players don't care to play as engineer and regard the class as just some mere support whose damage contribution is inconsequential. There's some truth to that, but I think that it's one of the more versatile classes out there and requires some smart (and fast) thinking to be a really good at it. For me, I find playing engineer to be very enjoyable and it also helps that I'm currently stuck with a terrible ISP, so the auto-aim of the sentry works well with my ping problems.

For the most part, the engineer places his buildings and lets his sentry do the work. Any new player can do the basics of playing engineer. However, as with all other classes, there are plenty of small things that you can do to set yourself apart from the average noob. Low skill floor, but higher skill ceiling.

The engineer benefits from two class mechanics available in MvM that aren't available in PvP:

• He can instantly redeploy buildings without waiting for it to slowly rebuild
  
• He maintains normal speed when hauling a building

These 2 mechanic changes really help the Engineer class become much more versatile in MvM.

However, to ensure that the sentry isn't too broken, the sentry's natural ability to apply knockback was taken away. Too bad, so sad.

I'm not one for the drudgery of a class basics guide. I'll try to focus more on some advanced tips and give my take on my preferred loadouts and upgrade path.

For more in-depth guide for engineering basics, you can check out this guide by The Killer Duck

http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=202746899

You can also check out CAR_'s guide for some basic nest placement.

http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=269131530

As with any class, equipping yourself with the correct weapons that are geared towards MvM usually provides a good starting point. However, loadout will only play a small role in your overall success as a teammate. Skill always trumps loadout. I always hate this section of writing a guide. I'll just quickly summarize what I think about things.


Rescue Ranger
Clip: 4
-50% max ammo on wearer

This is the go-to utility weapon for the Engineer. It's the most common primary to see because of two reasons:
1. Shooting your sentry with it heals 75HP 60HP per bolt.
   
2. Right clicking on your sentry within Line-of-Sight from afar will pickup your sentry. Costs 100 Metal.
However, it's downside is this:
• The engineer will be Marked For Death when hauling a building an a short duration afterwards. This causes incoming damage to be minicrit.
This primary really opens up some versatility for the Engineer. Long range healing and hauling is paramount for maintaining your buildings.

Frontier Justice
Clip: 3
No random crits

The primary works well in MvM due to the large amount of kills your sentry is bound to get. When your sentry gets kills/assists it will build up a counter. When the sentry is destroyed (even manually), the engineer will gain up to 35 "Revenge Crits". Each shot will do crit damage until you run out of Revenge Crits. Dying will reset the amount of Revenge Crits you have to 0. You can easily build up to 35 revenge crits in MvM. Each full crit will do 180 damage. It's very powerful. It's a very fun playstyle for sure, but hard to really utilize to it's fullest.

It's biggest fault is that it's not the Rescue Ranger. You're trading away better ability to maintain your buildings for a potential to make the Engineer's primary into a really strong burst weapon. Sometimes you'll be tempted to use your revenge crits, causing you either to be too aggressive and die, or you'll ignore your sentry/dispenser and they'll go down. I think overall, it's not as useful as Rescue Ranger, but feel free to try it out.

Widow Maker
Endless Clip
Uses metal for ammo
Hitting refills Metal

It's actually a very fun weapon to use. You're usually going to completely ignore your sentry if you're going to try to utilize this weapon. If you want to use it, I suggest using a gunslinger for mini sentries so that losing a sentry won't be a big deal to you. It's not playing at full potential, but damn is it fun.

Although, try it out for certain early waves. Most noteably is Disintegration Wave 1. It's 100 melee heavies. That means your sentry isn't really in trouble and the endless clip is really awesome for shooting stupid melee bots.

Panic Attack
Weird mechanics, but sort of cool
+50 reload rate
stores bullets in clip until you release M1, much like Beggar's Bazooka.
Firing Speed increases as health decreases (fastest speed at <25HP)
Bullet spread increases as health decreases

Again, this suffers because it isn't the Rescue Ranger. Mechanics like this almost automatically makes it a niche use weapon. The only use it ever gets from me is the rare ocassion of using it for tank-busting (explained later)

Wrangler:
Using it creates a shield around your sentry that absorbs 2/3 of incoming damage
Increases firing rate of the sentry
Allows manual control of where the sentry will fire. Has snap aim-assist.
Can allow the sentry to fire outside of it's normal range.

The standard secondary for the Engineer. You can find plenty of situations to use this for tanking or increasing damage for single targets. Just the fact that the shield can absorb 2/3 of incoming damage is a huge enough reason to use this secondary. I'll talk about it further in a later section

Short Circuit:
Use metal to destroy projectiles

Niche use for neutering certain projectile bots such as rapid fire crit soldiers. It works very well for these situations up until the point that you run out of metal. However, it can be very risky, where you put yourself in a dangerous position. It also takes your attention away from your buildings and your buildings can easily be destroyed while you're busy destroying projectiles. Overall, there's only a few situations where you can find true use of the Short Circuit. Otherwise, wrangler is better.

Stock
No upside or downside

I normally use the stock. It has no upsides nor downsides. The main reason I use it is because still retains the ability to random crit

Jag
Faster swing speed
Reduced repair
Takes 3 hits to remove a sapper

The Jag is better for quickly rebuilding your buildings up manually due to the increased swing speed. However, it doesn't have any random crits and it's weaker. It takes 3 hits to remove a sapper. It's not terrible, but I'd rather use stock. Only a personal preference

As usual with my guides, I'll group upgrades by priorities instead of suggesting strict upgrade routes.

High Priority

• Dispenser Range
  
• Building Health
  
• First point of Metal Capacity
  
• Wrench Attack Speed
  
• 2 or 3 more ticks of Metal Capacity
  
• First tick of Sentry Firing Speed

Medium Priority

• Crit Resistance
  
• Firing Speed / ClipSize / Reload Speed on Rescue Ranger as you see fit (if that's what you are using)
  
• Second tick of Sentry firing speed (only if you're using the wrangler....which you basically should be)

Low Priority

• Blast/Bullet Resistances
  
• Movement Speed
  
• First tick of Metal Regen
  
• 2-way Teleporter

Very Low Priority

• Disposable Sentry
  
• Others

The engineer is standard in most successful teams due to the dispenser providing ammo and health to teammates. Upgrading dispenser range only costs $100 and really helps dispense to teammates through a large radius. It's quite the 'bang for the buck'. A dispenser without dispenser range upgraded is annoying since it forces you to stand in one spot on the map to receive health/ammo.

+100% Building Health is listed next because it's the other 'bang for the buck' upgrade. You can double your buildings' (especially sentry's) health for a mere $400. It's just a really great upgrade for the cost. It's very important to keep your buildings up and Building Health is the best upgrade towards achieving that goal...especially early wave.

Next, 1 metal capacity is usually a good idea. Since the Gun Mettle update, repairing/refilling your buildings takes an increased amount of metal. You may constantly find yourself out of metal with only 200. It's also important so that you have the ability to construct both a sentry and dispenser at one time without having to run for an ammo pack.

Wrench speed is important since it increases the speed with which you repair/upgrade buildings, but also helps during the situations where you need to contribute tank damage. Depending on the mission, you may not need max wrench speed (such as Manhattan, which has no tanks) and may benefit more from more metal capacity. Test and see which works with your style.

At the moment, the sentry firing speed upgrade is broken due to the way damage is calculated and how ticks are rounded.

UNWRANGLED, ONLY THE FIRST TICK WORKS!
UNWRANGLED, ONLY THE FIRST TICK WORKS!
UNWRANGLED, ONLY THE FIRST TICK WORKS!

Even then, it's only +10% firing speed for $350. It's definitely not as good of an upgrade as Building Health, which only costs $50 more.

THE SECOND TICK OF SENTRY FIRING SPEED ONLY "WORKS" WHEN YOU WRANGLE!
THE SECOND TICK OF SENTRY FIRING SPEED ONLY "WORKS" WHEN YOU WRANGLE!
THE SECOND TICK OF SENTRY FIRING SPEED ONLY "WORKS" WHEN YOU WRANGLE!

These should be your most basic upgrades. Try to focus on these upgrades at the start.
The other upgrades listed can come in whatever order, but I do suggest that the "High Priority" upgrades come first.

Crit Resistance is always a good choice. Engineer usually stays in the back and doesn't need to directly engage any enemies. The sentry does the work. That's why Blast/Bullet resistance aren't that important to begin with. The engineer just needs to adjust positioning in order to be successful without these resistances. Crit Resistance is the exception. It's a very efficient resistance with 30% reduction each $150. It is also important because if you are using the Rescue Ranger, you are 'Marked for Death' when you are a hauling buildings, which makes damage received to be minicrit. Crit Resistance will help with that.

I like to spend cash into upgrading my Rescue Ranger. I normally upgrade Firing Speed first. Then your choice between Clip Size and Reload Speed. It's good so that you can use the bolts to heal your sentry at a fast pace. You do not always need to be firing though, so you don't exactly need the Reload Speed upgrade as you can just reload during the idle portions of the wave. Also, using the Rescue Ranger to heal is a great way to conserve your metal. Repairing your buildings with the wrench can chew through your metal fast. If possible, just use your rescue ranger to repair the health, and then use your wrench to refill the sentry if need be.

I'm a big fan of movement speed on Engineer. It's great for dodging damage (especially when hauling buildings while Marked for Death), and allows you to move your buildings in and out of the battlefield faster.

First tick of metal regen can be good. I normally don't purchase this upgrade because I think my metal management is pretty good - I just run to a dispenser or ammo pack if I'm running low. However, some may find the passive regen useful.

Two-way teleporter is nice later on in the game if your teammates need to return to spawn during the wave for whatever reason (mostly for more canteen spam). It's actually very rare where you'll use it to catch a Super Scout.

Disposable Sentry is very expensive and doesn't provide much DPS. Definitely not an early wave upgrade, but that doesn't mean it's a totally useless upgrade. You can buy it later waves. Just do not put it all the way up front. It needs to off to the side where it will rarely draw any aggro. It will self-destruct when it runs out of ammo and can't be destroyed manually.

====NOTE====

Dispenser range is almost always a good idea to upgrade. However, it does not have to be MAXED right away.

• Hamlet Hostility starts with $700. Buy 1 Building Health, 2 Dispenser Range, and 2 Upgrade Building Canteens.
  
  
• Empire Escalation starts with $900. Buy 1 Building Health, 2 Dispenser Range, 1 Metal
  Capacity, 2 Building Canteens.

Two ticks of Dispenser Range is good enough in a lot of situations. If you were to buy 3 ticks for Wave 1, you would either have to trade away the 2 building canteens or the Building Health upgrade. Basically, do not pidgeonhole yourself into thinking that an Engineer MUST get max dispenser range as your first upgrade. Depending on Wave 1 starting cash, usually two ticks (perhaps even one tick) can be good enough.

However, in non-Two Cities/Big Rock missions where the waves only start with $400, it usually is best to max dispenser range and then buy 2 building upgrade canteens. Again, it's not mandatory. Some people may just do 2 dispenser range and then 1 tick of metal capacity/wrench speed instead.

You can look up in other guides where the "standard" spots are to place your buildings at. They serve as a good primer to starting out as engineer and are usually good places to put your buildings. However, it's more important to understand the basic reasoning behind where you should place your buildings and then you can figure out your own preferred areas of building placement.


The teleporter, as in PvP, helps keep your teammates at the frontline even after respawning. It's used to eliminate any time teammates spend running to the enemy when they should be at the frontline fighting. To this effort, the entrance and exit should be placed in an efficient manner to save the most time.

Teleporter Entrances
Every single official map has two spawn doors. It's normal that the entrance is placed halfway in between the two spawn doors. It's also normal that you place it behind some sort of cover in the rare case that it gets hit by bots if they make their way to the hatch. However, you don't actually have to place it at the halfway point. As long is the entrance is not in some ridiculously far off place that people need to waste time walking to it you're fine. You can even place it much closer to one spawn door than the other. Just inform your teammates to pay attention which spawn door it's next to.

Someone once complained when I placed a teleporter entrance closer to one of the spawn doors in Rottenburg rather than in the "normal" spot.

"I had to walk 2 extra seconds to the teleporter"

True....from that spawn door. If you spawn from the other spawn next time, you'll have to walk 2 seconds less that time. It evens out in the end. Just place it in the middle if you want to avoid conflict and having to explain yourself over and over. :)

Teleporter Exits
The teleporter exit should be placed in area where your teammates can be transported to a good defensive area on the frontline while still being safe. This means the teleporter exit should be placed behind cover so that it isn't damaged by any stray bullets/explosives.

===IMPORTANT==
To find a good spot for the teleporter exit, you must also think about the situation where more than a few of your team dies at the same time. Most likely you will lose some ground and the bots will progress up the bomb path. If your teammates now teleport back to the front, will they be in a compromised position behind the bots? The teleporter can't be ALL THE WAY at the front. This is why it's normally best to leave at least some buffer space so that if your teammates teleport back to the front, your team can now take up defensive position without being pinched behind the bots

It's almost important to note: BOTS DO NOT TARGET TELEPORTERS. They only damage teleporter as collateral damage when shooting at your teammates. They do not aggro teleporters. The only exception are robot engineer's sentries. Those sentries have a different aggro system and WILL shoot at teleporters in their range.
==============

If the bots do end up pushing past your teleporter exit, don't forget that you can always rebuild your teleporter exit at your new defensive position. Since teleporters don't draw any aggro from bots, you will most likely have to manually destroy the old teleporter and rebuild a new one. This mostly applies to bigger maps such as Big Rock or Rottenburg

The building that is the big justification of Engineer's slot in most team. Without the dispenser, I doubt most teams would run with an engineer. The dispenser provides such a convenience to the team that it is usually seen as the Engineer's most important building

Any engineer with half a brain knows that the dispenser should be placed for the team rather than for the engineer. It's used to provide health and ammo to all teammates in range. The engineer is a class that does not need to be on the front lines and is quite free to move around without any detriments to the team. Engineers can easily run to ammo packs or run to a dispenser that is further away from his normal spot. The main damage dealers should rarely be worrying about their ammo count. Giving up a good position to go find an ammo pack or making a long trip back to the dispenser can really end up costing the team. This is very true during crucial moments where teammates might be caught out of position all because they were looking for ammo.

• One of your main jobs is to reduce the amount of times your teammates have to go looking for ammo

For wave starts, the dispenser should:

1. Be in the frontlines
   
   
2. Be at place where it's dispensing radius can serve the most amount of people
   
   
3. Not be completely vulnerable to fire. To do this, the dispenser should be either:
   
   • behind some kind of barrier/cover to help prevent damage
     
   • positioned off to the side from where your teammates will be defending, most noteably where the heavy will be defending.
     
   • Not be exactly in the bomb path. Remember that Giants instantly destroy dispenser and teleporters if they happen to walk on them.

On the flip side, you may not want to position your dispenser in a spot that is overly aggressive. This can cause your teammates to set themselves up in a compromised position that is hard to defend. It really depends on the skill level of the team.

It's important to note that the dispenser DOES NOT need to always be behind cover. If your teammates are defending at a forward location that doesn't have a barrier to hide the dispenser behind, it is perfectly fine to move the dispenser up out into the open...as long as your teammates are closer to the bots than your dispenser is. THE DISPENSER IS LOW ON THE AGGRO LIST. This means that robots would rather shoot your teammates than your dispenser. Of course, this is true provided that your teammates are not hiding/dead, which would then make your dispenser the only thing for the robots to shoot at.

This fact applies mostly to spots in Rottenburg, Manhattan, and Coaltown. The dispenser will do fine in a "vulnerable" position as long as your teammates are nearby and still alive.

Some examples:

Rottenburg:



Manhattan:


Plus, it's OK for the dispenser to take damage. A level 3 dispenser has 216 health - the same HP as a level 3 sentry. Will full building health upgrades, that's 864 HP. It can take a decent amount of punishment before it goes down. DON'T BE A WIMP, MOVE THAT DISPENSER UP!


If you want to be a hero engineer, it's very essential that your building positions are not static. One big difference between a novice engineer and an experienced is engineer is that the novice will very rarely move his buildings. What a travesty. An engineer should always be thinking about where he should next move his buildings to serve his team. You serve as a mobile ammo supplier. Don't make your teammates move to the dispenser, instead move the dispenser to the team. This depends of course on if you can do it safely, but in most situations you just need to find the correct (safe) path to get your dispenser up to your teammates in the heat of battle. Take advantage of the instant redeploy times available in MvM mode.


The dispenser has a limited supply of metal. Whenever it provides metal, the supply goes down and if it reaches empty it will stop dispensing ammo to teammates. Try not to let it deplete all the way down if you can. It's important that sometimes the engineer goes for the ammo pack instead of trying to replenish all of his metal through the dispenser. Remember:



This provides no ammo/health


This will provide ammo/health


Along the same train of thought, sometimes a lvl 1 dispenser is good enough for the team. A level 1 dispenser still distributes ammo/health sufficiently to your teammates. A lvl 1 dispenser has less health, distributes ammo/health slower, but it really is good enough for most situations. If you find that your dispenser has been destroyed, it is acceptable to only rebuild a lvl 1 dispenser from scratch and then switch to doing something else. You can upgrade the dispenser over time later on when you have a free moment. You don't need to set a dispenser and then immediately waste a Building Upgrade canteen.

The engineer can't only be used for dispenser. He also needs to help contribute damage in order to 'pull his weight on the team'. Luckily, the engineer has his trusty sentry to be his surrogate in the damage dealing department.

Sentry placement ends up being very lenient. There is no real rule to sentry placement besides this:

• IF YOUR SENTRY IS NOT ALWAYS FIRING, THEN YOU'RE NOT THE MOST EFFICIENT YOU COULD BE

Anytime your sentry is sitting idle and not shooting, that represents something that could potentially be improved...unless of course there's no bots on the map at the time. Your sentry shooting 100% of the time that bots are present on the map represents Maximum Efficiency. In reality, you can't always be 100% efficient and there will be times where your sentry needs to babysit the bomb or you need to pull your sentry back to repair. That's fine, but you should always strive towards Max Efficiency. This is why spawngineers (engineers who place their buildings at the hatch to start) are not utilizing their sentry effectively.

When deciding where you should place your sentry, keep these things in mind:

• A lvl 3 sentry has 216 health. With all 3 ticks of building health upgrades, the sentry HP becomes 864. While the sentry is being wrangled, a shield around the sentry absorbs 2/3 of incoming damage. This means that while wrangled, the effective health of the sentry is 2594. The sentry can withstand punishment. The sentry also tends to draw a lot of aggro from bots, especially Giants. Sometimes you want the sentry to draw the aggro to take the pressure off of your teammates.
  
  
  
  
• Sentries are affected by damage falloff. Normally both bullets and rockets damage is scaled based upon the engineer's distance to the target. The exception is that while wrangled, the sentries bullet damage is based upon the sentries distance to the target.
  
  
• Sentries ignore crit damage. This makes sentries incredibly powerful against bots such as soldiers with constant crits. While teammates might get wrecked by crit bots, the sentry can withstand the punishment quite well
  
  
• Sentries ignore heal-on-hit effects. This makes sentries powerful against bots such as concheror soldiers or blackbox soldiers. They will gain nothing from damaging your sentry.
  
  
• It takes time for sentries to lock on to a target and then fire. Sentry's targeting is less effective when trying to fire on groups of fast targets that are changing their angle to the sentry too fast. Basically, don't place the sentry in a spot directly behind a corner where it will only begin to lock on to targets that are already close to it. You'll find out quickly that this is a bad idea. Sentries work best when placing it in a position where it can utilize it's full sight-line.
  
  
• Sentries suffer very little from bullet spread compared to other hitscan weapons. This means that they have an advantage when fighting a hitscan opponent at range and even if wrangling from a far distance, you can still hit most of your shots. Setting the sentry at range and using the wrangler to fight against a hitscan bot at a distance gives you the advantage.
  
  
• If you're using the rescue ranger, this will allow you to pick your sentry up from a distance within LOS. The sentry can be placed very aggresively to start and later moved back if needed. Don't be afraid to get aggressive.
  
  
• Having a height advantage is almost always a good idea. It helps prevent splash damage and prevents some other bots (melee/pyro) from getting in range to damage your sentry. There's also a small advantage you can exploit that I'll try to explain further later in the guide.
  
  
• The sentry is essentially another teammate. The sentry should fight alongside your teammates. It should not be too far forward nor too far back from where your team is. The exception is when the bomb has been pushed back towards the hatch. Unless your team has pushed all the way up to a single chokepoint, the engineer is normally assumed to be the one to babysit the bomb. But during the wave, your sentry should almost always be where the bomb is if the bomb has made some progress. The only time it isn't is when the team has effectively pushed forward to a chokepoint and you redeploy your nest there.
  
  
  
  I like to place the sentry directly over the bomb. It's funny sometimes

Overall, I end up reacting a lot to the situation and the sentry will be moved throughout the wave. Again, if you're not moving your buildings - you're probably doing it wrong

Also, I might place my sentry in one spot at the start of most of the waves, but then position it at an entirely different position for certain waves. This is normally because I've played the waves enough to know that certain sentry spot works better. In short, just because one spot is a good spot for most waves, doesn't mean that it's a good spot for every wave. The same rule applies to the dispenser.

Any decent engineer is expected to know how to sentryblock. This is the act of placing your sentry in a position on the bomb path where Giants will run into the sentry, halting their movement momentarily. The bot AI will cause the robot to jump after a few seconds of being 'stuck' and they will usually jump on top of your sentry and continue on. It's most effective to be used on Super Scouts, but can be used on any Giant to great effect.

I wrote an entire guide on the subject, indicating most of the well known spots, including videos of gameplay on different maps showing its effectiveness.

http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=230713208

Here are some of the video highlights if you're too lazy to read.

Rottenburg:


Mannhattan:


Decoy:


Big Rock (only a few):


=====

Here's some new videos

Rottenburg 2 (Blocks in the back-half of the map):


Open-field blocking:

This is done by using both your sentry and yourself to wedge a giant to a halt. All you need to do is place a sentry directly in the bomb path, and as the bot moves to the side to go around the sentry, run beside him to wedge him in. This doesn't quite work when the giant is targeting your sentry though. You'll probably get killed this close to him from splash or from his aggro turning to you.

Standing on the sentry:

Not very useful, but funny to see anyway

Not getting your sentry destroyed by a sentry buster is pretty elementary - move your sentry away as the buster is priming to explode. Anyone with more than a few matches under the belt should understand that basic principle.

However, there are a few other situations that I think are worth discussing.

1. Your dispenser is down. Your sentry has reached the threshold where sentrybusters are showing up at a fast pace

• Some players might be tempted to rebuild another dispenser and use an upgrade buildings canteen. Don't. You could, but you're still stuck with sentrybusters being spawned at a high rate. Instead, what you can do is allow the current sentry to be destroyed by bots or sentrybuster. Then you can rebuild both a sentry and dispenser and use an upgrade buildings canteen.
  
  When your sentry has reached a threshold where it's kills/damage done are high, sentrybusters will continue spawning until your sentry is killed - either by bot or buster. That will reset the counter and you can breathe easier for a while without sentry busters spawning. Manually destroying your sentry WILL NOT reset the threshold.
  Reference Thread
  
  So instead of just using your upgrade buildings canteen to only rebuild a dispenser, let your sentry die to reset the sentrybuster threshold and then use the canteen to make a new dispenser and sentry.
  
  Also important to note is that the threshold will automatically reset in between waves. There's no need to rebuild a new sentry for each new wave thinking that you're resetting the threshold.

2. Your sentry is set up for blocking incoming Super Scouts. However, a sentry buster is spawning at roughly the same time

• Here, there are three options.
  
  First, you can leave your sentry at the blocking spot. Your sentry will block the scout at it's position, and the buster will start to explode. Use the rescue ranger to pull your sentry back at the last second so that the buster damages the Super Scout. Usually this can work fine as long as your teammates aren't standing nearby your sentry. Also, since your sentry is probably blocking near the front, the smokescreen from the sentrybuster exploding can be annoying for your team.
  
  Second, you can deal with sentry buster as normal. Hopefully your team can take care of the Super Scout.
  
  Last, once you recognize the problem situation is coming, you can quickly relocate your sentry away from the team and manually destroy it. You can then quickly rebuild a new sentry in the block spot. The sentry buster logic will cause it to run to where the previous sentry was just manually destroyed and blow. It's a shame to waste a perfectly good sentry, but sometimes it's the safe play to make to ensure the Super Scout is denied and your teammates are not in danger of being blown up

Even with as much time I've spent playing Engineer, ocassionally teammates still get killed by Sentry Busters. Sometimes its because I try to be as efficient as possible and leave my sentry firing for a while before setting off the buster at what I deem to be a safespot. However, some teammate who isn't paying attention just wanders into that space and dies. Usually I just chalk it up to their fault. Theoretically you COULD just waste a lot of time pulling your sentry FAR away from your team and setting off the buster there...but that represents lost time without your sentry contributing. I try to avoid that as much as I can, but really it's also the job of each teammate to be aware of their surroundings. Some teammates are just completely clueless and run directly in to sentry busters. I especially dislike teammates who seem to back pedal and follow sentry busters. Meanwhile you're standing there with your sentry like an asshole thinking "Should I just set this buster off? This guy is stupid"

======

Also important of note is the situation where a Sentry buster is just spawning. However, your sentry gets destroyed by bots on the map. As mentioned, the buster will go to the spot where the sentry was...regardless if you now build a new sentry or not. Most teammates don't pay attention to this kind of stuff. You need to tell them "Get away from the spot where the sentry was" . Otherwise they may just continue standing there oblivious, get blown up, then say "What the hell, Engie?" even though it's not your fault at all. (debatable)


The sentry busters can be used by the medic to farm ubersaw hits. This is most true when a sentrybuster is spawning during an idle period of the wave. If you have your sentry up on a rock or if you're carrying the sentry and standing on a rock, the buster will usually continuously try to run up the rock, but will not be able to - resulting in it essentially standing still. The medic can easily farm ubersaw hits during that time before the sentrybuster self destructs from standing in one spot for too long. You could also run busters around in circles until the medic gets all of the ubersaw hits he needs, but that's usually annoying.

However, not all medics use their ubersaw to farm hits - especially in pubs. On premade teams, yes, it's good to work with the medic so that he can get free ubersaw hits. On pubs...it's hit or miss. Sometimes medics chase the buster too long and get themselves killed, sometimes they just ignore the buster.

Or you could lead a buster into a glitched spot where he gets stuck.

For the most part, you will really only be using Building Upgrade canteens to instantly upgrade all of your buildings to level 3. For only $50, it's a very powerful canteen.

It's very normal to keep a stock of Building Canteens on you nearly at all times in the early waves. The canteens are that advantageous. However, in later waves when you have wrench attack speed upgraded, Building Upgrade canteens are not as necessary. You can quickly rebuild a destroyed building back up to level 3 within a few seconds with full wrench speed.

Remember that any cash spent on canteens is cash that cannot be spent on permanent upgrades. Spamming canteens will quickly drain your cash supply and you might suffer in later waves since you cannot buy the necessary upgrades to keep up with the increasing difficulty of the waves. However, the Engineer doesn't require that many upgrades to fulfill his role. His main role in the team will be supplying ammo and health through his dispenser:

Dispenser Range ($300)
Building Health ($1200)
1 tick Sentry Firing Speed ($350)
Wrench Attack Speed ($800)

^These are really the core of Engineer's upgrades. Almost everything other upgrade can be seen as a convenience upgrade. Therefore, Engineer is pretty cheap to upgrade and will probably have a lot of extra cash that he COULD spend on Building Upgrade canteens if he wanted to.

Some people like to play without using Building Upgrade canteens at all, which is fine. However, during the early waves you can really suffer and find yourself without a sentry/dispenser at a crucial moment.

Later waves, you could switch it up to different Canteens.

• Uber Canteens make the user invulnerable. It also adds the wrangler shield around the sentrygun. The sentrygun will still auto-aim and can be repaired/refilled normally without the normal wrangler shield penalty. However, they're expensive, you might as well just continue buying Building Upgrade canteens in my opinion.
  
  
• Crit Canteens causes all damage the user inflicts to be crits. It also makes the sentry fire at max firing speed. These canteens can be great if you're attacking a tank.
  
  
• Ammo canteens aren't too useful to the engineer. They can be useful for refilling ammo/metal, but they don't refill the sentry/dispenser's supplies unfortunately. The only real use I can see for them is if you've got your Rescue Ranger upgraded. Since ammo canteens will instantly refill your clip when you use it, if you've got a 12 clip fast firing rescue ranger, you could essentially shoot out 48 bolts to heal your sentry without ever needing to stop to reload. All you would need is to use 3 ammo canteens. Very situational, but something to think about.
  
  
• Nothing really stands out that's unique to Engineer when it comes to Teleport to Spawn Canteens. I suppose if you're stuck building at the hatch and having some problems with having enough metal to get your buildings up, you could use a Teleport to Spawn canteen to quickly restock your metal/health/ammo count to full to use. Very situational as always

=========

Half of the time, I'm not even using Building Upgrade canteens for rebuilding. There is another attribute of the canteen that I prefer to take advantage of:

• Using a Building Upgrade canteen will also refill all of your current building's health to full instantly.

Think of this situation:

Your sentry is tanking damage. It's in a spot where it's just about inevitable to be destroyed. You could let the sentry die, quickly place a new sentry down and use your Building Upgrade canteen. You're down 130 metal. That's a lot in the early waves, especially Wave 1 if you don't even have a Metal Capacity upgrade.

Or you could use your Builiding Upgrade canteen right before the sentry goes down and refill the health all the way back to full. This time, you still used a canteen, but you haven't used 130 metal. The drawback to this though is that your old sentry still has the same ammo to it (which may be depleted by now). However, if you went with the option of building a new sentry, it would have spawned will full ammo count.

The other drawback to this method is that since your sentry was not destroyed, the sentrybuster threshold was never reset. Keep that in mind when deciding if you want to keep the current sentry up or if you wish to just let it die and quickly rebuild a new one. (Thanks to HerrJon for the suggestion)

Between an upgraded rescue ranger healing your sentry, wrangler nullifying 2/3 of incoming damage, and a Building Upgrade canteen instantly refilling the sentries HP to full, the sentry is able to tank quite a lot of damage.


Wave 2 Bavarian Botbash is one of the best times that your sentry should go full tank-mode. The 3 banner brothers are tough to deal with because:

1. The buff banner causes them to do minicrits
   
2. The concheror causes them to heal on hit

The sentry will ignore both of those effects.

The Rescue Ranger is a very commonly used primary for the Engineer in MvM. The ranged pickup and the healing bolts really help to make the engineer very versatile. It's the ultimate utility weapon for engineer to use in his primary slot. Others can work very well, but the Rescue Ranger really opens up a lot of opportunities for the Engineer.

As stated earlier, if you want to play engineer towards his full potential, your sentrygun should be firing at all times that bots are on the map. It should very rarely be in an idle position. To accomplish this, your sentry will basically always be on the front lines along with your teammates. Playing aggressively like this, it may be hard to keep the sentry up without the help of the Rescue Ranger. The Ranger allows you to fire bolts at the sentry that heal it for 75 HP 60 HP each. Since the Gun Mettle update, healing/refilling a sentry with your wrench takes an increased amount of metal. You can quickly find yourself with 0 metal if you are always heailng the sentry by hitting it with your wrench. In order to combat this, you should attempt to heal the sentry with the Rescue Ranger bolts as much as you can before using your wrench to refill the sentry ammo. This advantage alone can help tremendously in the early waves.

Upgrading your Rescue Ranger should be thought of as basically upgrading the speed at which your can heal your sentry from afar. I normally increase firing speed up to max first, followed by Clip Size / Reload Speed depending on how I feel at the moment. Sometimes Reload Speed isn't important since you can just reload during parts of the wave where you're really doing much or the one of your buildings don't need attention.

There are also some situations where staying near your sentry and whacking it with a wrench is just not a safe idea. This is true when there are large groups of explosive classes that are spawning. A lot of times if you're near your sentry, the splash damage will kill you since Engineer rarely invests a lot of cash in resistances. During these times its much better to just back up away from your sentry and heal from afar.

The Rescue Ranger is also great because it allows the user to pickup buildings from a long distance as long as the user has Line Of Sight with the building. Essentially, this allows your sentry to tank damage, but at the last moment before the sentry is destroyed, it can "blink" suddenly back to you and you can repair it. Pretty sweet. However, this doesn't just happen on it's own. Part of being a good engineer is prepositioning yourself at a spot that has LOS of your sentry, but is also near a corner that you can duck behind once you pull the sentry back. The bots who are currently aggro'ing on the sentry, will follow the aggro back to you when you first pull the sentry, so be prepared to duck behind cover immediately after rescuing your sentry.

*Haha, I was supposed to edit out the ending part where I botched it and got killed. Oh well, too lazy to go back

Movement is key to doing this properly. You should already be thinking about where you want to position yourself to rescue your sentry. It's also important that you know the maps well. You want to be able to navigate the map backwards. Normally you'll be backpedaling while shooting your sentry with the Rescue Ranger to heal it. Engineer and Medic are real backpedaling classes that require good movement while still facing the front. If you don't know the map layout well, you'll have a more difficult time utilizing the Rescue Ranger to it's fullest.

The advantages of wrangling:

• Shoot enemies outside of the normal range of the sentry
  
• Increases sentry firing speed
  
• Wrangler shield nullifies 2/3 of incoming damage

The advantages of auto-fire:

• Better tracking for fast moving targets
  
• Frees the engineer up to do other things such as repair the sentry or attack with the wrench

Auto-fire will always have better aim than if you were to wrangle. Even though the wrangler has a snap aim-assist, it will not be able to track enemies as well as auto aim will. Auto-fire also switches to new targets instantly and is much more effective in dealing with crowds. This is why it's normal for the engineer to let the sentry autofire for any kind of small bots. Using the wrangler is actually a little rare for me. I use it in the follow cases:

1. There's a giant that needs to be focused on or he's basically the only bot worth attacking at the moment
   
2. The sentry needs to tank some damage for the team (against Giant Banner Soldiers or Giant Blackbox Soldiers for example)
   
3. To fire on a sniper outside of the sentry's range
   
4. Playing expert where it's sometimes very difficult to keep the sentry alive so you need to play a little more conservative

I suppose I should mention that when you switch off of your wrangler, the sentry will experience some "downtime" before it switches back to auto-fire. Any novice engineer should already know the way to avoid this is to pick up the sentry and then place it right back down, which will force the sentry back into auto-fire. Also, because this is a quick way to get rid of the shield, it also gets rid of the repairing/resupply penalty that comes with the shield being up. Don't waste time repairing a sentry that still has it's shield up. Instead, quicky redeploy it before repairing.

====

Then there's this choice when the sentry is tanking damage:

• Sit behind the sentry and whack at it with max swing speed
  
• Continue to wrangle until it gets low and then repair it.

Before the Gun Mettle update, sentries could still be repaired at the normal rate even with the wrangler shield up. Now, the repair/refill rate is reduced by 2/3 if the wrangler shield is up. I would have said that option #2 was the clear winner before the Gun Mettle update. These days, it's not as clear. I still say it's better just to wrangle the sentry and repair it when it gets low. Sitting behind your sentry makes you vulnerable to splash damage. Not only that, what if your repair rate can't keep up with the damage being dealt? The sentry dies, and bots aggro you quickly thereafter and you'll wind up dead before you know it. Wrangling the sentry while positioning yourself to Rescue it and then duck behind a corner if need be is still the better option in my opinion.

In my mind, this is how this exploit of bot AI works. Excuse my basic paint skills

The soldier AI targets a place on your sentry hitbox, probably somewhere in the middle or lower. He fires a rocket towards that spot, but the ledge is in the way.

This screenshot from sigsegv shows soldier bots targeting a point on the sentry very close to what I had estimated on my pictures
http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=573091756

The sentry targets the soldier bot and fires back. However, the sentry bullets originate at a higher level and are able to make it over the ledge.

I sometimes use this on Rottenburg, most notably this spot;





A similar situation occurs when there is a chain link fence to hide behind.
You can find situations like this in Big Rock:


===

I found this nice graphic on another guide written for PvP Engie showing the advantage of hiding the hitbox:


Source:
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=390538574

(update 6-24-2016)
Here's this in action:
Sergeant Crits shooting the fence like an idiot

Here is an even better view of what is going on. The soldiers try to hit the sentry but cannot:

And here is that same sentry positioning used to neuter the Giant Rapid Fire Soldier of Wave 3. Bonus: It also distracts the pyros who would otherwise mob your teammates.

Occasionally, you'll find yourself without a dispenser up. It's gone down and your teammates are probably running low on ammo. You either don't want to use a building canteen or don't have anymore on you. So what do you do?

You can quickly drop metal scraps near where your teammates are. All you need to do is start building a dispenser near where your teammates are stationed, and then manually destroy it immediately after. The metal remnants of the building serve as small ammo packs. You are basically spending 100 metal to drop a group of metal scraps on the ground for your teammates to pick up.

Another way to look at it is that you're transporting ammo to your teammates, especially when you grab an ammo pack to fill up your metal and then go and drops dispenser gibs for your team to pick up. Also since ammo packs fill up based off of %max, and an engineer is likely to have increased metal capacity, it's a very efficient use of that ammo pack compared to if just one of your teammates had grabbed it. That small ammo pack might be worth 300 metal to you, which can be translated into 3 seperate dispenser gibs that supply the entire team with ammo.

Of course you still want to get the dispenser up, but in the rare case that your teammates need ammo quickly, your building gibs can serve as a quick ammo distributor.

^This isn't an actual in-game scenario, but you get the idea.

A level 3 sentrygun is very powerful early game. Unlike the other core damage dealers, there are not many upgrades to increase the DPS of the sentry. There are only 3 ticks of "+10% firing speed" available to the sentrygun. The first tick works, the second tick only really applies when using the wrangler, and the third tick doesn't work at all due to tick rounding. In a practical sense, that means you can only increase your sentry DPS by ~11% unless you're constantly using your wrangler (which isn't THAT often). However for the early waves, the sentry has some very powerful DPS coupled with its auto-aim ability that excels at kiling fast moving targets. It's not very uncommon for the engineer to have the highest damage at the end of Wave 1. However, during later waves other damage dealers will be able to increase their DPS through upgrades to a much greater extent and your sentrygun's DPS will lag behind.

This is the sentry by itself. Of course the engineer can increase the DPS of his own weapons through upgrades, but it's not as practical against the smaller bots as your buildings will take up most of your upgrades and maintaining them will also take up most of your attention.

However, the Engineer along with his sentry makes a very solid tankbuster. Not many people realize this. You'll find a lot of Two Cities teams that place the Soldier and Demo on the tank. Not a good idea.

I wrote a guide about how Engineer is a better option for sending on the tank in Rottenburg

http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=484369172

I have plenty of screenshots that show engineer top damaging on the tank through multiple playthroughs of Rottenburg. The trick is whacking the tank with your wrench full time while the sentry is shooting the tank at the same time. The total DPS from that method is somewhere around 410, which puts it towards the top of DPS charts. Read the guide for further details.

Here's a video about it:



Also pointed out in the guide is the niche use of the Panic attack for tankbusting. It has insane burst damage.

Certain playstyles that work beautifully in Advanced missions don't necessarily apply in Expert. Due to reduced available credits and upgraded AI bot skill level, very aggressive playstyles are dangerous and failing at it is more punishing. Therefore, it's normal to play more conservatively in Expert and really utilize spamming chokepoints.

The sentry still has a great DPS early waves, but in most situations is unable to tank as much as in Advanced. The inability of the sentry to dodge becomes quite the disadvantage and you might find your sentry being destroyed quickly if you're too aggressive. The dispenser really does become your greatest contribution to the team and the sentry plays a much more supportive role. One of the biggest contributions of the sentry may just be it's solid sentryblocking ability on Super Scout waves. Also the sentry really is the best at babysitting the bomb, so sometimes it's just better/safe to leave the sentry protecting the bomb from single scouts getting passed your frontlines instead of moving the sentry all the way up front with the rest of your team.

It doesn't help that Engineer continues to get the short end of the stick in the Gun Mettle and Tough break updates. Now with the nerfed RR healing and Jag nerf, the sentry is harder and harder to keep up these days.

Summary: The dispenser being up is much more important in Expert. Aggressive sentry spots are much riskier and not advised. However, you're always free to do what you want.

Also dispenser placement is important. The team normally coalesces around the placement of your dispenser and/or sentry. If you place it in a spot that causes your teammate to position themselves overly aggressive, it can really come back to bite you in the ass. Try to utilize chokepoints much more.

Work In Progress section.










Playthrough of Hamlet Wave 1

The results of that Wave 1:


====

Playthrough of Bavarian Botbash Wave 1
This team is much more experienced and aggressive.

The results of that Wave 1:


Then end of mission:

Tired of the same old Mann Up tours? There's only so many times you can play it before it becomes boring. The game mode has amazing potential, but very little support from Valve (beside breaking something every update).

Thankfully, there are tools for both creating your own maps and creating custom MvM missions including custom bots. However, there is a lot of ♥♥♥♥ out there. People are making custom MvM missions with no regard to actually making it challenging. It's mostly gimmicks and usually not very fun.

However, there is a community that is interested in actually making challenging missions as well as custom maps that present different strategies. These help keep the game mode fresh and exciting, with dedicated servers that run them. The problem will always be that it is a niche community with servers that can't be found through the in-game matchmaker.

Here are some groups that are dedicated to Custom MvM:

Potato Servers

• This group is currently the big group for creating and testing Custom MvM missions. There are 3 (more or less) server instances running custom MvM maps at all times maintained by Hydrogen. They constantly make new events for playtesting Custom Missions that can range from normal to expert.
  
  As a little sideproject frontlined by Woozlez, a group is trying to put together an update package to submit to Valve for a community MvM update. At the moment, they have a fullset of missions for 3 custom maps and are looking to put together the cosmetic side of the update on this thread[facepunch.com]

Custom_MvM

• This group is a smaller group mostly from us dickheads that frequent the MvM subforum. This group was originally made for organizing games for playing Custom MvM missions on both Potato Servers and sigsegv's custom server, but now that Potato Server's group has added in event-creating functionality for their members, there's a little bit of overlap.
  
  We mostly run our game testing on sigsegv's server. Most of the missions are supposed to be Expert, although some are just Advanced. You can find the list of custom missions that are on sigsegv's server here. I will vouch for the majority of the members knowledge of MvM and all of them should be solid teammates to play with.

Interested in creating your own custom MvM Missions? Here are a few references that you can use.

http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=376575386
A good primer for getting started creating your own custom MvM Missions.



http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=572409016
sigsegv's comprehensive guide about the actual effects of AI bot difficulty. Every mission maker should read this.

I hope you've learned a few things from this guide. It can get quite long if you include all of the external links/guides that I wanted you to read as well. There are a lot of small things you can do to set yourself apart from the typical noob engineer. The main take-aways I'd like people to get from this guide are:

• Be aggressive with your sentry (less so in Expert)
  
• The dispenser is low on the aggro list. You can move it out in the open as long as teammates are near it
  
• Engineer is a very solid tank buster class. Sentry + wrench whacking is very powerful
  
• Don't overuse the wrangler. Autofire is better for general crowd control
  
• Engineer doesn't need too many resistances. Adjust your positioning and let your sentry and teammates take aggro
  
• Sentry is very good for tanking damage. Utilize the fact that sentries ignore crits and other heal-on-hit/kill mechanics.
  
• Always try to position yourself toward where you'd like your next sentry position to be in the case that you get pushed back and have to quickly pull your sentry with your Rescue Ranger and redeploy it.
  
• Learn to sentryblock. Damn
  
• If you're not moving your buildings throughout the wave....you're probably doing it wrong.

I've probably forgotten to include many things. Feel free to tell me about it