The Custom Backpack Dropper is a modification for Quake made by Chris Sobotkiewicz. Using five different impulse keys (impulses 50-54), the player can set up a Backpack that can supply other players from the initial player's stock. This is useful to supply teammates with resources that the other player does not need, thereby allowing for better balancing of resources. Note that the player must have the resources to give, or they will be unable to produce said Backpack.
Impulse 50 defines the particular mode. The player can switch between the 4 Ammo types and Health. Impulse 51 is used to define the incremental values, meaning one Ammo will be added each time the player presses the key. Alternatively, they will be able to give 15 Health or 25 Health, though the box will always appear the same as a 15 Health. Impulse 52 cycles through the Weapons, while impulse 53 is used to toggle the active one in the cycle from impulse 52 is added to/removed from the Backpack. Impulse 54 is used to spawn the Backpack with Ammo/Weapons and any 15 Health/25 Health included.
Note that this modification only works in Multiplayer, these impulses do not function in the Single Player game. Furthermore, there is a message that appears for the client that states that this modification is running, though it appears twice.