Players cannot choose preset or custom classes. They all start with a Skorpion and an M9.
There are sprites (yellow glows containing items) around the map which have weapons, equipment or perks that the players can pick up. Once a player picks up a weapon or perk from a sprite, it turns red, then the sprite regenerates the same weapon, perk, or equipment after a set period of time.
All weapons have double the size of the magazine, except for the PC version of the original Call of Duty 4: Modern Warfare where the player does not get more ammo.
Players have double health. Two knife hits are required to kill a full health player.
Players can jump twice the normal height and falling damage is negated. Many players use this to get out of the map more easily.
When killed, players get wildly pushed into the air.
Old School FFA on Wet Work COD 4
This game mode is much like a typical arena shooter. The name "Old School" most likely refers to earlier days of FPS games in which players had significantly more health than in CoD games, and often had to pick up weapons from the floor.