Common variants include changing the dimensions of the field, using a circle instead of a square for the clear line, a stall count of 5 or 7 (instead of 10), and a "no poaching" clause which prevents defenders from guarding the endzone instead of their assigned player.
A variant originated in Washington, DC, Boot-Box, combines Double box with the cone hitting game, Durango Boot.
Invalidimate was developed in the UK as a way to include injured players in practice; the "invalid" stands in the goal and is the target receiver for both teams.
A drinking variation called Beer Box was invented at Case Western Reserve University in Cleveland, OH.
Similar to standard box, a goal is scored once the offensive team caught a pass in the endzone.