Return to Player (RTP) is an important metric for selecting slot machines, representing the percentage of wagered money expected to be paid back to players over time. Higher RTP values indicate better long-term payout potential, making those games more appealing. However, RTP is calculated over many spins and doesn't ensure specific results for individual plays. It's essential for players to consider RTP alongside personal preferences like volatility and game themes to choose slots that offer both enjoyment and good winning chances.