Developers don't pick RTP numbers at random. They come out of game design, business strategy and regulation, which is why two games that look alike can carry very different price tags.
Volatility and game design
Volatility describes how a game's RTP is spread out, and two slots can both sit at 96% yet feel nothing alike. Low-volatility games pay small wins often. High-volatility games give you long dry spells broken by the odd big hit. Dead or Alive 2 is the classic high-volatility example, with plenty of losing runs in the hunt for a huge payout, while Starburst is known for steadier, smaller wins that keep a session ticking along.
High RTP doesn't promise frequent wins, and low volatility doesn't automatically mean better returns. The two numbers work as a pair, and together they set the feel of the game.
Features and mechanics
Bonus rounds often carry a big chunk of a game's return, which is why free spins matter so much in modern slots. Progressive jackpots skim part of every bet into the prize pool, which usually leaves the base RTP lower. Bonus buy features, which let you pay for direct access to the bonus round, vary widely by game and operator, so check the info screen rather than assuming. Slots that advertise enormous maximum wins tend to get there through low base RTPs and high volatility.
Provider choices
Studios differ in how generous their games tend to be, but returns vary more by title than by brand. Many providers release the same slot in several RTP versions, so you might find one game at 92%, 94% and 96% depending on the casino. The operator chooses which version to offer.
Regulation and tax
The UK Gambling Commission does not set a minimum RTP for slots, so levels here come down to competition and operator choice. Other regulators set their own rules, and they vary by jurisdiction. Tax matters too: where bets are taxed before the outcome is decided, operators have a reason to trim RTPs to protect their margins. That's why the same game can pay back different amounts depending on where you play.
One UK rule worth knowing, although it's separate from RTP: online slot stakes are capped at £5 a spin for players aged 25 and over (from 9 April 2025) and £2 a spin for 18 to 24-year-olds (from 21 May 2025). The limits cap what you can stake per spin, not what you can win.
Where you play
Online casinos often offer higher RTPs than land-based venues, helped by lower overheads and fierce competition. Physical machines carry the cost of space, staff and upkeep, and locations with a captive audience tend to be the least generous. Operators also segment their lobbies: steadier games with solid RTPs for casual players, and high-volatility titles with lower base RTPs for jackpot chasers.
