A Match bonus is the most common type of bonus. For every $ you deposit, you will be credited X% of what you deposited by the casino. So, if, for example, casino Z is offering a 100% match bonus, deposit $100 and the casino will give you an extra $100 in bonus money. This means that actually start playing at the casino with $200. Match bonuses are almost always limited to a certain maximum bonus amount you can claim.