A $20 casino bonus and a $20 cash deposit can look identical in your account balance. They aren't. On a standard 30x wagering requirement, that $20 bonus locks up $600 in required play before it converts to withdrawable cash. The same $20 deposited as cash has no strings — you can withdraw it, or what's left of it, the moment you want. That's the entire gap in one line: the bonus costs four times the playthrough because the requirement applies to the bonus, not to your deposit.
Where the multiplier actually comes from
Wagering requirements get quoted as a single number, which hides the math. A "30x" term is meaningless until you know what it multiplies. Three common structures:
- 30x the bonus: $20 bonus × 30 = $600 playthrough
- 30x deposit + bonus: ($20 + $20) × 30 = $1,200
- 1x deposit + 30x bonus: $20 + $600 = $620
The first is the most common in US-facing promos. The second is the one that quietly doubles your obligation, and it's the one to check for in the terms before you opt in. The third looks generous and usually isn't — it just shifts the load back onto the bonus.
So when someone says a $20 bonus "costs 4x the playthrough of $20 cash," they mean $600 versus $0. Cash has no playthrough. That's the baseline. Every dollar of required play is a dollar you're exposing to house edge.
What $600 of play actually costs
Playthrough isn't free. You're running money through games with a built-in edge, and the expected loss compounds with volume.
Take a slot at 96.2% RTP — a realistic mid-range figure, not a headline number. Run $600 through it and the expected loss is $22.80. That's more than the bonus itself. You'd need to clear the wagering and still have a balance above zero to come out ahead, and at that RTP the math says you're slightly underwater on average.
Now run the same $600 through a 97.4% RTP slot. Expected loss drops to $15.60. Through a 94.8% RTP game — common on some progressive and jackpot titles — it jumps to $31.20. Same bonus, same $600 requirement, a $15.60 swing in expected outcome based purely on which game you pick.
This is why game weighting matters as much as the headline RTP. Many bonuses count slots at 100% toward playthrough but table games at 10% or less. A $10 blackjack hand might only retire $1 of your requirement. If you're a table player, a slot-tuned bonus is close to unusable.
The cash comparison nobody runs
Deposit $20 cash, no bonus, and you owe nothing. Play the same $600 voluntarily and your expected loss is identical — $22.80 at 96.2% RTP. The difference is you could have stopped at $40. Or withdrawn at $25. The bonus removes that choice until the requirement is met, and if you bust before clearing it, the playthrough was wasted effort on money you never controlled.
There's a second cost: time. Clearing $600 at $1 per spin is 600 spins. At four seconds each, that's 40 minutes of continuous play — and most people don't clear a bonus in one sitting. The longer it drags, the more likely you are to play past the requirement out of momentum rather than intent.
When a bonus is still worth taking
Bonuses aren't a trap by default. They're worth evaluating when the requirement is low relative to the bonus, game weighting matches how you actually play, and the maximum cashout isn't capped below what you'd reasonably win. A $20 bonus at 30x with a $100 max cashout is a different proposition than the same bonus with no cap — the cap changes the ceiling on your upside.
The honest test: divide the playthrough by the bonus. $600 ÷ $20 = 30. If that number is high and the RTP of your preferred games is low, you're paying for the bonus in expected value, not receiving it.
Which raises the question worth sitting with — if a $20 bonus and a $20 deposit both expose you to the same house edge over the same $600, what exactly is the bonus buying you? For some players, it's a longer session on the house's dime. For others, it's just a longer session. The terms decide which one you get.
If you do take a bonus, set a stop-loss before you start and treat the playthrough as a cost, not a target.