A plain-English walkthrough of every input, mode, and result. Read this once and the simulator will make a lot more sense.
The simulator runs an offer through thousands of simulated playthroughs and shows you the full range of outcomes, not just the average. The mean expected value is useful, but you also need to know how often you bust, how often you walk away with nothing, and how often you scoop a big result.
It exists so you can understand your real risk before you play. Two offers with the same EV can have very different variance profiles. One might hit target three times out of four, the other one time in four with bigger wins. The number on the front page does not tell you that. The simulator does.
Pick the one that matches the offer you are evaluating.
You deposit, wager a qualifying amount on a chosen slot to unlock free spins, then play the spins. Winnings from the spins may have a wagering requirement attached.
No deposit or qualifying wager needed. You just play the spins and any bonus balance through the WR.
You deposit cash and the casino adds a matching bonus. The bonus has a wagering requirement attached. This is where the wagering order setting matters, because there are several ways the casino might let you play through it.
This is the most important setting on a deposit match offer. Same RTP, same WR, same stake, but the wagering order can swing the EV and risk profile dramatically.
Your deposit and bonus are pooled into a single balance and wagered together. There is no protection on your cash. If the combined pot busts before the WR is cleared, your deposit is gone with it.
Your cash and bonus balance remain segmented and the bonus funds are used first for wagering. This is the best type of bonus but not very common anymore.
You play your own cash first with a profit target in mind. If you hit the target, you cash out and keep your winnings (the bonus is forfeit because you never started the WR). If your cash busts, the bonus is then used. Higher upside on the big runs, but you have to set a sensible target.
Target Profit is the amount of profit (over and above your deposit) that you would happily walk away with. For most modes this is optional and shows up as the "P(reach target)" stat. Leave it blank if you have no specific number in mind.
For Cash First it is mandatory because the mode is defined by it. If you do not set a target, the simulator does not know when to make you stop playing your cash and start wagering the bonus instead.
A sensible default is your deposit amount. If you deposit £20 and target a £20 profit, you are aiming to double up before locking in the win.
Volatility describes how often you win and how big those wins are. Same RTP, very different shapes.
Higher volatility does not change EV on its own, but it widens the gap between the P10 (bad run) and P90 (good run) outcomes. More wins lost to WR, more wins big enough to clear it with a flourish.
The toggle at the top right of the input panel.
Same inputs give the same result every time. Good for comparing two offers side by side, or tweaking a single input and seeing exactly what changes. The simulator seeds the random number generator from the input parameters so the run is reproducible.
Fresh random each run. The mean EV will be roughly the same but the histogram and sample paths will look different every time. Useful for getting a feel for the natural variance, or for sanity checking that Stable mode is not hiding any quirks.
The three numbers most players actually care about. Mean EV (the long-run average). Bust Rate or Std Dev (how risky it is). Avg Time (how long a typical run takes). Plus the histogram chart and a one-line summary. This is enough to decide whether to play.
Adds the median, probability of profit, probability of loss, hourly EV, the full P10 to P90 percentile strip, and the sample playthroughs chart. The fuller callout text also unpacks the spread and the skew. Use this when you are stress-testing an offer or comparing variance profiles in detail.
The arithmetic average expected value across all simulations. Positive means the offer is in your favour over the long run. This is the headline number but it hides everything about variance.
The share of simulations where the balance went to zero before the WR was cleared. A bust rate of 30% means three runs in ten ended with nothing to show for them. Lowering your stake reduces bust rate but increases the time required.
How often the simulation hit your Target Profit and would have cashed out at or above that level. Shown as a percentage and as a target card above the metrics.
P10 is the result at the 10th percentile, meaning 90% of runs did better than this and 10% did worse. P90 is the reverse. The gap between them is the "realistic" range of outcomes for a single attempt. A wide P10 to P90 spread means a volatile offer where the average is a poor guide to any individual run.
The default is 10,000, which is enough for a stable distribution shape on most offers. For sharper averages, especially on very high variance offers or those with rare jackpot tails, run 50,000 or 100,000. Lower sim counts (10, 100) are useful for seeing the feel of individual playthroughs but the headline stats wobble around.
Everything the simulator outputs is the expected value across many offers, not a guaranteed outcome on any single one. A positive EV offer can still lose on the day you play it. That is variance.
If you are new to this, work through the academy articles on EV, variance, and stake sizing before relying on simulator output for real decisions.
18+ only. Gambling can be addictive. Please play responsibly. BeGambleAware.org
Record your profit and expected value