Betting is a type of sport in Murder Mystery 2 mainly intended to promote the game.
Most bets are on private servers, where there are only 2 players, although there are other ways to bet.
Classic bets are usually on private/VIP servers, so that one player is the murderer and one is the sheriff. The bet is usually given to the player who wins.
Time bets are used on public or populated servers, in which each player must stay alive for a certain amount of time, being alive longer than the opponent. If one of the players in the bet is the murderer or the sheriff, it does not count.
A middleman is usually used to make sure you do not get scammed. A middleman is someone who gets both players' bets to make sure one does not scam the other by just leaving the server, although the middleman can scam both players or just one in the process. It is recommended to use a trusted middleman.
This is the most common scam in Murder Mystery, in which a player leaves as soon as the bet is over, if they lose.