In a three player game, often times players will agree on a time limit. Many times the time limit can start as soon as one player is knocked out of the game (For Example: 10 minutes after a player is knocked out, etc) or use a general time limit (For Example: one hour time limit). The tie breaker is determined by the amount of limbs a player has blown off. The secondary tie breaker is the amount of limbs a player has left. If there is still a tie, then the players continue play until one player blows off or regenrates another limb.
It is often a good idea for each player to use a die or a sheet of paper to keep track of blow offs (it can be hard to remember amounts later in the game).