Credits are piles of cash which drop when robots are destroyed in Mann vs. Machine mode. Regular robots drop small piles of cash while giant robots and tanks drop larger piles of cash. The amount of credits dropped per sub-wave is fixed, usually a multiple of 50 or 100, and is distributed equally amongst all robots in that sub-wave (for example, in a sub-wave of 30 robots that gives 100 credits, each robot drops either 3 or 4 credits that overall sums to 100). Normally, support-only classes (such as Snipers, Spies, and Sentry Busters) do not drop credits. Other support classes may drop credits up to a maximum amount at which point killing more of them will not drop any more, and if this maximum amount has not been reached by the end of a wave then all remaining robots of that support group will drop the remainder. Credits have sizes depending on how much is dropped; 9 or less drop a small pile of credits, 10-24 drop a medium pile, and 25+ drop a large pile of credits.
Credits can be used at Upgrade Stations to purchase weapon upgrades, abilities, and Power Up Canteen buffs. The majority of missions start players off with 400 credits, though several missions provide starting values of 900, 1000, 1200, 1500, or even 5000.
Players who have been killed have the option of buying back into the game early (default key: ) for 5 credits per second remaining with a minimum of 10 credits (e.g. the cost is 25 credits to skip 5 seconds of respawn delay and cannot skip the last second). The defending team is notified via a sound cue as well as a message in the chat box indicating how many credits were spent. Scouts respawn faster and thus have very little need for this mechanic.
If a player joins a game already in progress, they receive the total amount of credits that have been collected so far in the previous and current rounds of the game, including the starting credits.
Any class can run over a pile of credits to collect it, sometimes triggering voice lines encouraging other players to join in. Scouts have the ability to attract credits from about the width of a control point away, making it easier and faster to collect numerous piles. Scouts also gain health for collecting credits; the amount of health received is based on their current health. The health received starts at 50 at normal health and decreases as the Scout's health increases, down to approximately 5 health per credit pile at 700 HP and over. All credits collected are shared equally amongst all players; if a credit pile is worth 50 credits, all players gain 50 credits when any player collects it.
As the amount of credits dropped is dependent on the number of robots in the wave, the amount gained from a single pickup is not fixed and can vary between two otherwise identical piles. The total amount of all credit pickups active on the map is displayed underneath the player's current cash; this number appears green if no credits in the wave have been missed, and black otherwise.
Credits have an expiration time of 30 seconds and start flashing to alert players when they are about to expire after 25 seconds. When expired, the credits disappear into a puff of flame. If credits fall into a deathpit or similarly-inaccessible area (such as the tank-only tunnel in Rottenburg), they are automatically collected.
Robots killed by any Sniper primary (or the related Explosive Headshot upgrade) produce "red credits", which are identified by their dollar sign particle effect being red instead of green. Red credits are considered to be collected by the Sniper the instant they appear; while they remain in the world so Scouts can still collect them for health, they do not need to be collected by the team, and can safely be ignored once identified as red. This allows a Sniper to safely kill robots at a distance without the risk of the team being unable to reach and collect the credits they produce before expiry.
The number of credits collected in a wave is graded by the Administrator as a credit rating ranging from A to F. Collecting all credits dropped during a wave results in a credit rating of A+ and a bonus of 100 credits to each player. Collecting 95%+ of the wave's total credits results in a bonus of 50 credits to each player. The credit rating for an entire game is also tracked as the sum of all its rounds.
- Credits that have been picked up by a Scout's magnet, but not collected by the Scout (if the Scout dies before the credits reach him or they are sent into a corner), enter a bugged state where they can be picked up by the same Scout from any range, as long as there is a direct line-of-sight from the Scout to the credits. If the team has multiple Scouts, they are unable to use their own magnet ability to collect these credits, however they are still able to collect them by running directly over them like the other classes.
- Credits in this bugged state also ignore certain map triggers that normally cause them to auto collect, such as the robot spawn zones. If a pile of credits lands in an unreachable area this way, then the Scout who flung the credits there is the only player capable of collecting them.
Green dollar sign particle effect
- A Fate Worse Than Chess Page 31 - Official TF2 comic