A 20 Deposit Bonus is a promotional offer commonly found in online casinos and betting sites, where players receive an additional 20% bonus on their initial deposit. For example, if a player deposits $100, they would receive an extra $20, giving them a total of $120 to play with. This bonus enhances the gaming experience by providing extra funds to explore various games or betting options. However, players should be aware of the associated wagering requirements and terms to fully benefit from the offer. Always read the fine print before claiming any bonuses.