When you pick an online slot, knowing its RTP and volatility can save you from...

https://wiki-velo.win/index.php/What_Are_Expanding_Symbols_in_Slots%3F_A_Straight-Shooting_Explanation

When you pick an online slot, knowing its RTP and volatility can save you from surprises. RTP tells you the average return over time, usually around 95-97%, while volatility shows how wild or calm the wins might be