The Combo is a Good Company tactic in Team Fortress 2. Developed in secret by Imperial scientists, the Combo is a strategy reserved for only the most dire emergencies where victory must be achieved at any cost. As such, it exists as an ‘ace in the hole’ of sorts that does not see widespread use among Good Company.
The Combo consists of a Medic equipped with the Kritzkreig and a Soldier equipped with the Beggar’s Bazooka and the Battalion’s Backup. After the Soldier has done at least 600 damage, the Backup can be deployed to reduce sentry damage and knockback by 50%, reduce damage by 35% from all other damage sources, and negate critical hits entirely for the Soldier and any nearby teammates. On top of that, it boosts the regular max health of the Soldier to 220, and overhealed to 330. The Beggar’s Bazooka can fire up to three rockets in rapid succession, and fires every subsequent rocket slightly faster at the cost of accuracy. The Kritzkreig, of course, guarantees critical hits for 8 seconds after activation at the cost of no defensive bonus.
When these factors are combined and activated simultaneously , the Combo is in full effect. The initial triple-rocket spread can put out 810 damage in less than a second within a splash radius. This means that, if all three rockets strike the center of a group of enemies, 810 damage is the minimum damage the Combo can inflict, and that’s just in the first seconds of being active. Subsequent rockets can clean up any survivors and eradicate the enemy team in a matter of seconds. The traditional weakness of a Kritzkreig combo is that they are susceptible to all incoming damage, especially the Medic; however, with the Battalion’s Backup active, both the Medic and the Soldier (plus nearby teammates) gain considerable damage resistance that nearly guarantees that, at the very least, the initial deadly three-rocket blast will be deployed regardless of how the enemy team reacts. Quite often, the Combo will clear out an entire enemy team in seconds; not many strategies can consistently exterminate a full 12 person team.
However, the Combo is not without weakness. It is really only effective in extreme chokepoints (such as the entirety of Dustbowl, Hoodoo, Gold Rush, and some areas of Badwater), which means its efficacy in more open maps is dubious. Furthermore, the Combo does take quite a while to completely prepare and thus is susceptible to being eliminated before it can be deployed.
The Combo was developed sometime after the July 10, 2013 patch for Team Fortress 2 that significantly rebalanced the game. The Battalion’s Backup was buffed to provide additional sentry protection (+15%), and to build meter from doing damage instead of receiving it. Later, in the December 20, 2013 patch, the Backup gained the +20 max HP buff which enhanced the strategy.