A wagering requirement is the number of times the bonus amount must be staked before winnings become withdrawable. A $100 bonus at 35x means $3,500 in total stakes.
Two offers with the same multiplier are rarely equal. Game weighting decides how fast you clear it: slots usually contribute 100% of each stake, table games often 10% or less. A 20x requirement cleared on blackjack can cost more play than 40x on slots.
The third variable is the clock. Most operators give 7 to 30 days; an unfinished requirement forfeits the bonus and its winnings. Before claiming, divide the total stake by your comfortable session stake — if the number of sessions does not fit the window, the offer is not for you.