Online Slots Explained: Reels, Features and Volatility

Online slots are the most popular games in online casinos. They range from simple three-reel games to complex video slots with many features. This page explains the parts of a slot and the terms you will see in the game information.

Reels and paylines

A slot has a grid of reels, usually three or five, sometimes more. You win when matching symbols land on a payline, a line across the reels. Some slots use fixed paylines, others count every combination of matching symbols on adjacent reels from left to right. The paytable shows what each combination pays.

Common features

• Wild: substitutes for other symbols to complete a winning combination.
• Scatter: pays or triggers a feature wherever it lands, usually free spins.
• Free spins: spins played without staking extra, often with enhancements.
• Multipliers: increase the value of a win.
• Cascading reels: winning symbols disappear and new ones fall into place.
• Jackpots: fixed or progressive prizes that are much larger than regular wins, but very rare.

The random number generator

Every spin is decided by a random number generator at the moment you press the button. The spinning reels are an animation. Each spin is independent: a slot is never due to pay out, and previous results do not affect the next spin.

Volatility

Volatility describes how wins are spread out:

• Low volatility: frequent small wins, a steady balance.
• High volatility: fewer wins, but sometimes much bigger ones; long dry spells are normal.

Two slots can have the same RTP but feel completely different because of volatility. Learn about RTP in RTP and house edge.

Before you spin

Open the information screen to check the RTP, the features and, where shown, the volatility. Many slots can be played in a free demo mode first. Choose a stake that fits your budget so you are not done after a few spins.

Slots are fast, which makes it easy to spend more than planned. Set a budget and time limit and take breaks. More tips are in responsible gambling. Gambling is for adults (18+) only.