With video screens in place of actual reels, modern slot machines are primarily electronic. To provide independent and impartial results for every spin, theind. slotsy make use of random number generators, or RNGs. These slots have a variety of themes, progressive jackpots, bonus features, and free spins. Slot machines usually feature three or five reels with different symbols displayed on them. Paylines are the lines where combinations with a chance of winning can appear.