A 300% deposit casino bonus is an enticing promotion that significantly boosts your initial bankroll. When you make your first deposit, the casino matches it with an additional 300% in bonus funds, allowing you to play with four times your original amount. For example, if you deposit $100, you'll receive an extra $300, giving you a total of $400 to wager. This generous offer enhances your gaming experience, providing more opportunities to explore various games and increase your chances of winning. However, always check the terms and conditions, as wagering requirements may apply.