The basic format of online tournaments is as follows. The player is given a starting tournament chip stack and a set time is allowed for wagering. These two parameters are identical for all players so as to ensure fairness. The player wagers in any manner he chooses on the designated game till his time is over or till he loses all his chips. If he loses all his chips then his score is zero, otherwise it is the value of the chip balance at the end of the time allotted. The players are ranked on a leader board according to their score and the winners are the top players on the leader board.

This basic structure has one drawback. If a player is unlucky right at the beginning of the tournament he can lose his chips very quickly and will derive no pleasure from the tournament. In order to give such players continued participation some online tournaments allow them to buy a fresh stack of chips. Such tournaments are called rebuy tournaments and the price paid by the player for the fresh stack is called the rebuy fee. In most cases the rebuy fee is equal to the entry fee and the new stack of chips has the same value as the original one. Most rebuy tournaments allow multiple rebuys. Some specify a limit on the number of rebuys whereas other tournaments let it be unlimited. So that the concept of rebuy is not misused certain rules are framed for the rebuy.  

Suppose that a player starts with a stack of $500 and is currently at $1,000. If he is allowed to rebuy at this point then he can increase his chip stack to $1,500 without wagering. This is clearly not the purpose of the online rebuy tournaments. Hence the stipulation is that a player will be allowed to rebuy only if he exhausts his chip stack completely. Therefore after the rebuy he will be at the same position that he was in at the beginning of the tournament and does not have any advantage. In practice the chip stack need not be completely depleted, but the rebuy is allowed at a minimal value of around $5 or $10 depending on the value of the chip stack. This does not defeat the purpose of the rebuy and allows players to continue with their betting pattern. Even when multiple rebuys are allowed the player can rebuy only one stack at a time.

Many low rollers feel that rebuy online tournaments are biased towards high rollers because they can use their bank roll to keep purchasing rebuys and are therefore more likely to end up with larger scores. This line of reasoning is not correct. A player purchasing 10 rebuys is the same as 10 different players participating in the tournament once each. And there can be no grouse with the second scenario. If 10 different people participate it is likely that one of them goes on to set a big score. If one player rebuys 10 times it is likely that he may set a big score in one of the 10 tries. What each player needs to do is estimate the number of rebuys he can afford before he starts the tournament and then stick to his decision.