Boarding is one of my favorite strategies in FTL; in this guide, I'll try to give some pointers as to how to successfully board enemy ships, what the dangers and limits are and some other things to take into account.

As a caveat, it needs to be said that this has been written before the Advanced Edition of FTL came out and has not been updated because I've not found the time to play since. I try to put in hints from people's comments.

The advantages of boardings are

• increased scrap collected from enemy ships
  
• ignores shield (except Zoltan shields)
  
• doesn't deplete ammunition (missiles or drones)
  
• small power consumption (often no need to power weapons)
  
• ability to choose new crew member race when having finished off a slaver by killing its crew
  
• sometimes random crew drops from any ship
  
• having a trained melee force also helps against being boarded
  
• unlocking of blue options for some events

• Danger of losing men in your away team
  
• Hull may take more damage
  
• Special dangers

With some practice and micro, you can avoid losing your boarding crew most of the time. In the end, you'll have to get a feel for how dangerous it will be to board a given enemy ship, depending on both your and their setup (systems, weapons, etc).

There are two aspects to the “more damage” point:
Firstly, it sometimes will take longer to kill off an enemy crew than to just blast away and destroy it. Again, this depends on both ships' setup: if your enemy has a large crew, boarding can take longer; on the other hand, if it has a high-level shields, it may take quite a while to just get through those with your weapons, and boarding will be faster overall. Secondly, when firing weapons to destroy the enemy ship, by targeting their weapon systems, you can decrease the damage they can deal to you over time.
Generally, boarding takes a fixed amount of time to beat any given ship, regardless of shields, while firing away takes longer against more shields. Consequently, boarding is a mid- to late-game strategy, because that's when ships with high shield levels will come up; in the beginning of the game (up until maybe sector 3), destruction by hull damage is usually faster and safer.

There are some special dangers in not-so-uncommon cases; these are discussed below.

All you need for basic boarding is

• Crew Teleporter system (duh!)
  
• A boarding crew (recommended Mantis for higher damage and Rock for higher HP)

The crew teleporter costs 75 scrap in shops; some ships start with it. It allows boarding with 2 men at a time for most ships.
Recommended for a boarding setup is a total crew of 6 (4 to man the stations, 2 for the away team).



The goal of boarding an enemy ship is to kill off its crew. To do that:
1. Move your men into the teleporter room
2. Select the “teleport” button (hotkey “T”)
3. Select the room in the enemy ship you want to teleport to
4. Members will engage with enemy crew in melee now.

Chances are that there are more men on the enemy ship than your away team consists of. In this case, your men will need several trips back and forth:

5. Select the “retrieve” button (hotkey “R”)
6. Select the room in the enemy ship you want to retrieve your men from
7. Move your men to your Medbay to heal.

Rinse, repeat, until all of the enemy crew are dead.

Teleport to and fight in rooms of size 2. This means that you fight 1v1 and won't take as much DPS as in larger rooms, where the enemy crew can mob up on your team. Also, you want to keep your men together in the same room in 99% of the time, if only to be able to retrieve them both after the teleporter cooldown.

These are the most basic steps; most of the time, you want to take out the enemy weapons first. To do that, fire a single missile or laser burst at their weapons system; this should disable it far enough to not be able to do your ship any relevant damage. Most of the time, you forcing the enemy crew into melee prevents them from repairing damaged systems. They might still manage to while you're back on your ship to heal.

Do Not set your weapons on Autofire (except Ion weapons). Ever. Especially not when boarding. If you miss or need more shots to pierce shields, fire again. Do Not Autofire. Unselect the button. If you need to autofire a specific weapon, hold Ctrl when selecting the target.
It's better to miss a shot you could have taken than to take one too many and lose your away team.



Apart from the upgraded teleporter which will shorten the cooldown period between consecutive teleports, very useful to have for boarding are

• Upgraded Sensors (level 2+)
  
• Upgraded Medbay
  
• Upgraded Engines
  
• An Ion or Laser weapon
  
• A missile or bomb weapon
  
• Healing Burst

The upgraded sensors allow you to see the enemy crew, which makes it much easier to assess the risk involved in boarding them. The upgraded medbay helps speed up the healing between boardings in a single battle.

Upgraded engines help in two cases: first, simply to evade any missiles fired at you like in normal battles; secondly, to be able to jump away faster if you think boarding isn't an option at all and using your weapons will put you in too much danger. You might have needed to neglected your weapons in favor of buying the teleporter and additional crew.

The Ion or Laser weapon is needed to penetrate Zoltan energy shields (see below). Ion weapons have the additional advantage that they won't do damage your crew even if they hit the room they're in, so you can put them on Autofire throughout the boarding action.

The missile (or bomb) weapon will be very helpful to board enemy ships with a Medbay (see below). It will also help by being able to shoot at the enemy weapons system to disable at least some of their weapons (you can do that with Ion and Lasers too, but that's going to be harder against high-level shields).

Healing Burst avoids you having to retrieve your men to heal, shortening the time it takes them to complete their mission (cfg. Steps 5-7 in “Basic Boarding” above).

Surprisingly often, one of your men takes much more damage than the other. Actually, it's not that surprising: the man on the leftmost square is always the one being attacked first. Knowing this can help you avoiding an additional cycle of teleporting back to heal if one of yours is close to dieing.

a) if there is only one enemy left, and you can win the fight against him with your other man, just move the damaged one out of the room. The fight will continue between the two remaining there.

b) if there is only one enemy left, and you can win the fight against him only with both your men, move them both to another room, but order the move for the less damaged one first. This will result in him going to the left, and he will be the one being attacked once the enemy followed you there.

c) enter a 2x2 room from the right side with Mantis (who are faster than the other races so they get into position early). The enemy following you will walk to the topleft square; while crossing the rightmost one to reach it, your men will get free hits on him. If it's a slow Rockman, you can easily get four hits (of double damage plus training bonus) this way...



It should be noted that when you engage the enemy crew in melee in any room, those men will not be able to do anything but fight the intruders. Most notably:

• Crew don't count as manning the station they're in
  
• Crew do not repair damage
  
• Crew do not put out fire

If your enemy has a well-trained crew, it will give them the same advantages you would get. Don't underestimate this: a level 1 man at the engine or helm gives an evasive bonus of +5%, which is as much as a full additional engine point - that's easily worth 50 scrap for mid-tier engines, even more for higher ones. If you board the helm, the pilot is now fighting and not counted as manning it anymore, so there goes the additional evade.

(Be advised that Happiness Officer points out that with regards to FTL charging, the helm does seem to count as manned even if the crew is fighting... I find that hard to tell, so to be on the safe side, it's probably best to assume he is right.)

If there is any damage to a station or a hull breach, those will not be repaired as long as the enemy has to fight your men in it - same for fires which won't be put out. I'm sure you noticed this, it's the same when you're boarded (especially annoying with boarding drones which always cause a breach you can't start fixing immediately).

Here are some ways to exploit that:



I mentioned this in the previous section already.
If the enemy ship has a Medbay, the best course of action is this:

• Send boarding party to any room but Medbay (I usually choose the helm - it's always two squares big and boarding it reduces evade)
  
• When the first man is wounded enough, he runs to the Medbay to heal
  
• Just before he reaches it, fire your missile (or bomb) there
  
• Move your men to the Medbay to prevent it being repaired

Optimally, the blast from the rocket kills off the man having just reached it on its own, and the Medbay gets destroyed. Two birds, one stone.



Breach bomb the O2 station, then board it. While the enemy is fighting your guys, they can't repair the breach and the air is sucked out of the room. Note that only after the air is gone completely (red/orange stripes) will it cause additional damage; after that point is reached, retrieve your men (or move them to another room if they still have enough HP to continue fighting).
Enemies moving in to repair will often not be able to fix the breach due to the damage they get from lack of oxygen; you won't even need to board again most of the time, you can just let them suffocate now (there's an achievement for that btw).

Needless to say this is only viable if your ship doesn't take hull damage from their weapons over time, whether because you took them out, due to a defense drone or enough evade and shields.



Firebomb the weapons room, then board it with Rockmen. The fire will slowly damage the system and give the enemy crew additional damage - and they can't put it out either. You can even go 2v4 for a while in this situation; the point is not to kill the men, but to let the fire get out of control. If four men are in the room, they all get the fire damage; once you retrieve your men, their crew is too damaged to extinguish the fire (if they don't have a Medbay, but even then it's often too late). And with the weapons room down, any ship is easy pickings...
If they do have a Medbay, do it there. At some point during the fight, the Medbay will get destroyed by the fire.


Neither of the two above tactics works against ships with system repair drones which are invulnerable to fire and don't need oxygen.



As Scop noted in the comments:
It is possible to send two crews down for boarding if you have an upgraded Teleporter system. Instead of retrieving your first two men from the enemy ship to heal, you send two more on there to cause additional havoc.

I cannot really recommend doing that because after the second team is sent down, the countdown is restarted, so it will take another cooldown to get the first team back. It's very risky, and risk is something you should be very wary about in FTL in general.
Another reason I don't normally do that is that I simply don't usually have a second team viable for boarding. Beyond my four men manning the systems and two boarders, I tend to have Engi as a repair team - and they make pretty much the worst boarders of all.
Thirdly, personally I'm upgrading the Teleporter only up to level 2 which is enough to always retrieve your men in time, but the cooldown is too long for the first boarders to live through two of them.
This is all my personal preference; try it out if you feel like it, but be warned.

If you ignited a room and have your first team of Rockmen in it with all the enemy crew staying clear of it because of the fire, your men are pretty much safe and you can speed up the whole process by sending in a second team to finish off the (now usually heavily damaged) enemy crew to avoid any more hull damage (if they still have missiles active for instance).

Note the retrieve will work on all men in a room - you can get all four of your men back if they're standing in a 2x2 room, even if your teleporter room isn't large enough; they'll be moved to adjacent ones.

There is one situation I can think of where it definitely makes sense, and that is when fighting the Mothership. The first team will take some time to destroy the missile station, and to speed up neutralizing its weapons, you can send the second one to the Ion station - or, in phase 2, the Beam - before the next cloak.

You want to avoid accidentally destroying the enemy ship while your men are still on board, or you'll lose them. It's really very simple: don't fire at it. I know I said it before, but it bears repeating, so: Do Not Autofire when boarding, ever.

It's also possible for your boarding crew to destroy the enemy ship by destroying a system (when a system icon changes from yellow to red due to damage, the ship loses a hull). This is a rather theoretical case, I don't think it ever happened to me. Just keep an eye on the enemy hull while boarding.

After you've played around with boarding a fair bit, you'll realize that it's rare for the enemy to lose more than half their hull if you play it right.

As This...Is...BACON! pointed out in the comments, special care has to be taken in Asteroid field encounters: the asteroids, which are not under your control, can also destroy the enemy ship. However, this really only happens if you shoot out their shields or disable them with continuous Ion fire; even a single shield point is enough to not take significant hull damage from the asteroids. So take care to leave their shield system intact.

And another addition by El Rushbo: the Federation Cruisers' Artillery Beam pierces shields, and will fire on its own - you don't target it yourself, so it's easy to forget. Remember to take its energy off completely when your sending your crew to the enemy ship.



You cannot board an enemy ship with Zoltan energy shields; you'll have to pierce it with your weapons first. An Ion Blast II is great for that due to the high fire frequency.



A functional Medbay on the enemy ship all but prevents you from successfully boarding them. You won't outdamage the healing of even a level 1 Medbay, and if you teleport somewhere else, the AI does a good job moving heavily damaged crew into the Medbay to recover.

See the "Destroying an enemy Medbay" in the "Advanced Tips" section above.



You cannot retrieve your men from a cloaked enemy ship. You need to be aware of how long the cooldown will still be active, how long the cloak is going to last and how fast your men are taking damage in their melee. If you decide too late to withdraw them, they are forced to stay and fight on the enemy ship, and if they take damage too fast, they may be dead before the ship comes out of cloak.

This can be pretty hard to assess; it's one of the main reason I still lose men in my boarding crew sometimes.



Upgraded doors prevent you from freely moving your men around the enemy ship. This is usually not an issue because most of the time you want them to fight, but there are situations in which you want to move them around to prevent damage until your teleport cooldown is finished (you can do that easily with Mantisses and their increased movement speed).

Just be aware if the enemy does have upgraded doors. I just lost a Mantis yesterday because I underestimated the damage he would take and I couldn't move him away from danger for a second or two due to the doors.



An enemy ship trying to run away (“Charging FTL”) will take your boarding crew with it if it manages to jump. Play it safe: losing two men at a time is pretty much the worst that can happen at once in the whole game. If the enemy FTL is charging, don't board him.

You can often enough destroy their helm first, then board safely; this puts you into pretty much the same situation as killing the Medbay I described above.

If your enemy has a Medbay and is trying to jump, it's going to be interesting. What works for me is: 1. destroy the bridge 2. board it 3. destroy the Medbay and move your men there. If it's timed right, you can even kill his men when entering the Medbay to heal by hitting them with your missile.



Drones are another system that may need taking out, anti-personel drones are quite the beasts. They regenerate in the drone system room and may even be recreated when one is destroyed. The good news is that due to the drone system, at least the enemy weapons tend to have less power, so you'll take less hull damage than usual.

It's hard to write a general case for boarding against a drone system because there are so many combinations of other drones and systems.



Be aware that your men take fire damage on the enemy ship as well. If you have Rockmen for boarding, that doesn't apply; see the "Firebomb Rock" in the above section.



They don't have an O2 system and your men will suffocate. Don't board them. You'll have to destroy them completely to win the battle anyway.



Again, watch out for suffocation. And again, see the section above how to make them work to your advantage.



Now there's a conundrum; do you use your trained melee specialists to board or to fend off the boarders?
Normally, defend first. You can take energy off the teleporter for that time, giving you more power for other systems; maybe a better weapon than normal to destroy the enemy weapons system?



Added in the Advanced Edition which I haven't played myself yet - but Happiness Officer points out that it's a very risky endeavor to board a ship with enemies able to Mind Control, and that you can't recall your boarders under its influence.



Having a boarding crew is great for defeating the enemy Mothership. Targets:
1. the missile launcher (second weapon from the right)
2. the Ion weapon (leftmost)
3. the Beam weapon (rightmost)

Neither the four shields nor the cloak will even matter, and you get it disarmed completely in three teleport cycles.

If you're feeling adventurous, you can try to take out the crew on the main deck as well. That's pretty tough; they have a high-level Medbay with four squares size... The breach trick I described above works fine, but breach the Medbay, not the O2.

Don't kill the whole crew though, let the Heavy Laser gunner live (second left); this way, the ship doesn't go into autopilot and won't autorepair. If you manage to do it, this makes the second and third encounter much easier, especially the third.

Thank you for reading, hope I could help some people a bit.
I'd like to add that this is all coming from experience that I nearly exclusively collected in Easy mode, so in Normal your mileage might vary; I'm sure the general principles are still sound.