For the new players of Dirty Bomb, I have put together a few pointers on how to work up your XP, in the hopes of getting those much needed credits faster to unlock mercs and acquire your most favourite loadout. Let me just say that although this game has similarity to TF2, it's got it's novelty in game mechanics by awarding you various XPs based on how you play. Of course, it's purely team based but in order to gain XP, you'll need to perform accordingly and this is how you rank up in levels and achieve points towards accomplishing your mission objectives. Although levels really means nothing towards game play, gaining levels are a sign of the basic player progression and playing in public gives other players the confidence when you're on their side and the opposing team has to pay more attention to you. Gaining various XP will make you more efficient in getting your mission rewards quickly and this will affect how you choose your squad when playing a map or a game.

• Game Mode XP
  Game Mode XP is gained by accomplishing in-game objectives whether it is primary or secondary. Planting or diffusing C4, repairing and destroying generators, capturing forward spawns, disabling, repairing or escorting the EV, or delivering the objective is how you gain this sort of XP. It's currently yellow (gold) and you get max XP gain when it gets highlighted. Engineer class mercs are more efficient in gaining this type of XP compared to other mercs (Turtle, Proxy, Fletcher, Bushwhaker). The Mechanic augment helps non engineer class to get this XP faster. You also gain Game Mode XP by successfully defending objectives and the longer your defense is, the more Game Mode XP you gain.
  
  
• Combat XP
  Combat XP is gained through the combat mechanics. This is probably the most fundamental XP you can gain in the game, and it is achieved when you make assists and/or kills. Currently, it's dark orange in color and and a highlighted one means you gained a very big chunk of the XP for the kill (usually if you get more than 100XP). All mercs are capable of gaining Combat XP, however, Assault class are mercs that are specifically oriented towards them like Fragger, Thunder, Rhino and Nader. Killing Rhino, Fragger or Thunder will award the highest Combat XP achievalbe to date, due to their high health pool.
  
  
• Support XP
  Support XP is gained by making supporting actions such as helping a player up, spotting with SNITCH or Heart Beat Sensor, passing/dropping med packs, reviving or passing/dropping ammo. For support class like Sparks, Sawbonez, Arty and Skyhammer, additional support XP is awarded if you pass ammo or medpacks that hit the player directly. It's color is cyan and if it gets highlighted, then you gain a big chunk of the XP reward for that action (usually greater than 100). Certain mercs like Arty, SkyHammer, Sawbonez, Aura, Sparks, Phoenix, Guardian and Kira are specialized mercs that gain higher than normal support XP so you should pay attention to selecting your squad when you need to do missions requiring Support XP. Further, you can now gain higher Support XP by helping up other playes, healing or reviving them through Health Insurance.
  
  
• Badge XP
  Badge XP is gained by exceptional game actions such as, First Blood, reviving 5/10/20 players, subsequent 6~15 kills, killing 3/4/5 in one air, artillery or orbital strike, 5/10/15 melee & finishes, 15 & 25 assists, , etc. You get a hexagonal notification onscreen when you get this. There are basically three colors: Dark Orange(Bronze, 150XP), White(Silver, 250XP) and Yellow(Gold, 500XP). Badge XPs are now added to either Support, Combat or Game Mode XP.

Why is the knowledge of these various XP important in playing DB? Because it helps you get your missions done more efficiently and if you want to earn credits quickly and to unlock mercs in the game, you'll consider mercs best suitted in gaining one type of XP than the other. The better your selection of mercs in the squad, the more efficient will it be for you to acquire your in game credits for playing DB and you can use them later to unlock mercs out of rotation, purchase standard boxes or even purchase the preferred bronze loadouts you fancy.

Another thing to consider is how a merc's stat affect the squad selection. Take for example, Aura or Sparks. To date, she and Sparks has the fastest sprint/movement ability , in game and although both of them not an objective specialist, she can move the data cores much faster than the rest of the mercs. Besides Sparks (for maps like later section of Bridge, Chappel and Trainyard), Aura can provide good support XP for the team by reviving and healing them with her health station. It's also a fact that AURA and RHINO make a very devastating pair (synergy). Aura gains a lot of XP from supporting Rhino if they're protecting an area because Rhino can tank and soak up a lot of damage while Aura's healing station keeps him from going down. In the event Rhino falls, she can revive him provided there is sufficient cover. Aura is however, not her best when it comes to tanking head on without much support. In contrast, SkyHammer is the basic bread and butter of DB, and he gets both combat and suport XP well in his skillset. Although not an objective specialist, you should be able to rake up the XP gain with just these two mercs.