Stock, also referred to as lives, is a Group match type present in the Super Smash Flash series in which a match is played based on a preset amount of lives, or "stocks"; players lose a stock after being KO'd or self-destructing. When a player runs out of stocks, they are defeated, and eliminated from the match. The last player or team with stocks remaining wins. If the final two players simultaneously lose their final stocks in Super Smash Flash, the match will end in a draw, but in Super Smash Flash 2, the players will enter Sudden Death.
The amount of stocks players have in a match can be set to any whole number from 1 to 99, and each player shares the same amount of stocks at the beginning of a match. The amount of stocks remaining for each player is shown at the top of their respective damage meter, which disappears entirely when the player runs out of stocks. During a Team Battle in SSF2, a player with more than one remaining stock can share a stock with their defeated teammate if they press the pause input, allowing them to continue the match. This stock system can also be used in tandem with a time match, with the winner determined by the total amount of stocks remaining at the end of a match.
The stock system also appears in certain Solo game modes. In Classic, Adventure, and All-Star, running out of stocks will bring the player to the Continue screen. In SSF, the amount of stocks a player starts with in these modes can be set from 1 to 5, but in SSF2 it depends on the difficulty level set, with higher levels having fewer stocks. In Target Smash, Multi-Man Smash, and Crystal Smash, the player starts with a single stock and the game ends if they lose it.