What is the house edge on slot machines?

It cannot be computed from outside the machine. The reel weightings that determine it are the manufacturer's and are not published, so no independent site can derive one. What is published is an RTP figure, which is a different and more limited claim.

Does a 96% RTP mean I get 96% back?

Over an enormous number of spins, on that exact configuration. It says nothing about a session, nothing about how the return is distributed between small frequent wins and rare large ones, and nothing about which RTP setting the operator installed.

Is a slot machine ever due to pay?

No. Each spin is independent of every spin before it. A machine that has not paid in hours is exactly as likely to pay on the next spin as one that just did.

Which casino game is cheapest?

Among games whose cost can actually be computed, blackjack played correctly at about 0.52% and the craps pass line at 1.4141% backed with free odds. Both are on this site with their working shown.

Slots: The One Game We Cannot Compute

Short version: a slot machine's cost cannot be computed from the outside. The reel strips and the weighting of each symbol are the manufacturer's, not published, and without them the arithmetic has no inputs. What operators do publish is a return to player figure, and that figure tells you less than it appears to.

Why every other page here has a number and this one does not

A deck of cards has 52 known cards. Two dice have 36 known outcomes. A roulette wheel has 37 or 38 known pockets. In each case the inputs are visible, so the output is derivable and this site derives it: that is what the methodology page describes.

A modern slot machine has none of that. Each reel is a virtual strip of positions, and symbols are weighted so that a given symbol may occupy one position or fifty. Those weightings determine everything and they are not disclosed. The physical reels you see, where reels exist at all, are a display of a result computed elsewhere.

So we publish no house edge for slots, and we would treat any site that does with suspicion, because the only people who can compute one are the manufacturer and the regulator holding the submission.

What a published RTP does and does not tell you

Operators and regulators publish return to player, the long-run percentage of stakes a machine returns. A 96% RTP means a 4% house edge over an enormous number of spins. Three things that figure does not tell you:

How long "long run" is. On a high-variance machine, RTP is a statement about millions of spins. Your session is not a sample of that distribution in any useful sense.
How the return is distributed. Two machines at 96% can behave completely differently: one paying small amounts often, the other paying almost nothing until a rare large hit. Hit frequency and volatility are separate properties and are usually not published at all.
Which configuration you are sitting at. The same machine model is often certified at several RTP settings, and which one is installed is an operator choice. A published figure for the model is not necessarily the figure in front of you.

What is worth knowing anyway

Jurisdictions differ in what they require to be disclosed. Some regulators publish minimum RTPs or aggregate returns by denomination; others publish nothing.
Progressive jackpots move the arithmetic and are the only case where a machine can, briefly and in principle, be positive. Finding that case reliably is not something a casual player can do.
Nothing about a machine's recent history changes its next spin. A machine is not due, and every result is independent. See why systems fail.
If you want the cheapest game on the floor and a figure you can check, it is on a table: blackjack at about 0.52% or the craps pass line at 1.4141% with free odds behind it.

Frequently Asked Questions

What is the house edge on slot machines?: It cannot be computed from outside the machine. The reel weightings that determine it are the manufacturer's and are not published, so no independent site can derive one. What is published is an RTP figure, which is a different and more limited claim.
Does a 96% RTP mean I get 96% back?: Over an enormous number of spins, on that exact configuration. It says nothing about a session, nothing about how the return is distributed between small frequent wins and rare large ones, and nothing about which RTP setting the operator installed.
Is a slot machine ever due to pay?: No. Each spin is independent of every spin before it. A machine that has not paid in hours is exactly as likely to pay on the next spin as one that just did.
Which casino game is cheapest?: Among games whose cost can actually be computed, blackjack played correctly at about 0.52% and the craps pass line at 1.4141% backed with free odds. Both are on this site with their working shown.

Every figure on this page is computed by side_games_math.py at build time and checked against the figures the industry publishes before the page is written. Where a number depends on the casino's own pay table, that is said rather than averaged away. Last computed August 2026.