The maximum bet is the largest stake allowed on a single round, hand, spin or selection. Every casino game has one, whether it is poker, roulette, video slots or anything else. The cap is set by the table, the game software or the operator.
At the poker table, betting caps keep the game fair for everyone. A player with deep pockets cannot bully the others into folding again and again by forcing them to bet more than they are comfortable with. On video slots, the maximum is coded into the game, and players simply cannot bet above it. Many slots also have a Max Bet button that places the top stake on all paylines in one click. For operators, the maximum bet is also a contract and compliance setting. Bonus terms often cap the stake while bonus funds are in use, and some regulators set a legal maximum.