A First Deposit Bonus in betting is an enticing promotion offered by sportsbooks to attract new customers. When a user creates an account and makes their initial deposit, the bookmaker matches a percentage of that amount, providing extra funds or free bets to enhance the betting experience. This bonus allows newcomers to explore various betting options with reduced financial risk. However, it's essential to read the terms and conditions, as wagering requirements and restrictions may apply before withdrawing any winnings derived from the bonus.