The wagering requirement (also known as playthrough or rollover) is the most important term in any bonus offer. It is a multiplier that dictates how many times you must bet your funds before the bonus turns into withdrawable cash. This mechanism exists to prevent players from claiming a bonus and immediately withdrawing it without actually playing.
There are two main types of wagering: Bonus-only, where only the awarded bonus amount is multiplied, and Bonus + Deposit, where the multiplier applies to both the bonus and the money you deposited. The latter significantly increases the total amount you need to bet to unlock your funds.
Your progress is tracked automatically by the system. For example, if you bet on a slot, the amount wagered is subtracted from your total requirement. The specific multiplier for any active offer is clearly displayed alongside the promotion in your account dashboard.