The essential slot machine terms, defined without jargon
This glossary gathers the technical terms you encounter when playing slot machines: RTP, volatility, wild, scatter, free spins, bonus buy and others. Each definition is written in a neutral way, without any advertising purpose, to help understand how games actually work.
Terms are sorted alphabetically. Each entry offers a short definition, a detailed explanation and, where relevant, examples drawn from games listed in our database.
What is RTP?
RTP (Return to Player) is the theoretical percentage that a slot machine pays back to players over a very large number of spins. An RTP of 96% means that for every 100 euros wagered, the game returns an average of 96 euros over the long term. This rate is calculated over millions of spins and does not reflect the result of an individual session.
What is volatility?
Volatility (or variance) indicates how often and how large a slot machine pays. High volatility means rare but potentially large wins; low volatility means smaller but more frequent wins. This data is published by some providers in their official technical sheets.
What are a wild and a scatter?
A wild is a joker symbol that substitutes for other symbols to complete winning combinations. A scatter is a special symbol that can trigger free spins or a bonus when it appears in sufficient numbers on the reels, often without needing to be aligned on a payline.