15-Minute Melee and 15-Minute Brawl are Multi-Man modes in Super Smash Bros. Melee and Brawl respectively. While they both challenge the player to defeat as many opponents as possible (Fighting Wire Frames in Melee, and Fighting Alloys in Brawl) within 15 minutes without falling from the stage or self-destructing, the player will find that it becomes a challenge to merely make it through the match alive. These are arguably one of the more difficult Multi-Man modes, as throughout the 15 minutes, the player can accumulate a great deal of damage and eventually be easily KO'd by a middling attack or rogue item, though simple strategies such as spamming a certain move or evading the opponents altogether may suffice (most infamously Donkey Kong's Hand Slap).
The high scores of 15-Minute Melee depend on whether or not the match is cleared. If it is cleared, a record is made of the amount of opponents KOd. If it is not cleared, a record is made of the length of time the player lasted. In 15-Minute Brawl, the only record that is displayed is KOs, regardless of whether the player finished the match.
Unlike 100-Man Melee/Brawl, in which the enemy difficulty increases after set numbers of KOs, the enemy AI in a 15-Minute Melee/Brawl will get more aggressive as time goes on, even if the player has no KOs. This serves to make it more difficult to "eat the clock" by evading enemies.