Gravity can set to Light or Heavy. In general, Light gravity allows characters to jump higher, fall slower, gain better recoveries, makes them less vulnerable to chain throws, and gives them decreased vertical momentum canceling abilities, while Heavy gravity gives characters shorter jumps, faster falls, shorter recoveries, increased vulnerability to chain throws, and increased vertical momentum canceling abilities. Special Gravity is independent of the Slow/Fast Speed options and both Gravity and Speed can be altered in the same match.
Special Gravity was first seen in Super Smash Bros. Melee, in which Stage 11 of the Adventure Mode featured a battle against the Fighting Wireframes with reduced gravity. Special Gravity is not available elsewhere in Melee besides through hacking.