Rules
Double Out in Darts
Double out means the dart that takes you to exactly zero must land in a double, or in the inner bull which counts as double 25. Reach zero any other way, go below zero, or leave exactly 1, and you bust: the visit is void and your score goes back to where it started.
What counts as a finishing dart
| Dart | Finishes? | Why |
|---|---|---|
| Double 1 to double 20 | Yes | Any segment in the outer ring |
| Inner bull (50) | Yes | Counts as double 25 |
| Outer bull (25) | No | Counts as a single |
| Any single | No | Not in the double ring |
| Any treble | No | Not in the double ring |
The three busts
All three have the same consequence and are worth separating anyway, because players recognise the first one and get caught by the other two.
- •Overthrowing. On 40, a treble 20 takes you to −20. Obvious, and rarely a surprise.
- •Leaving 1. On 20, a single 19 leaves 1. The lowest double is 2, so 1 is unfinishable and busts immediately — you do not get to throw again to fix it.
- •Zero without a double. On 20, a single 20 reaches exactly zero, but on a single. Bust. This one stings, because the arithmetic looks like a win.
The second and third together are why leaving an even number matters so much. On 32 you can miss double 16 into the single 16 and still be on a double. On 33 a single 16 leaves 17, and now you need a dart just to make the score even again.
Busting on dart one versus dart three
The score is identical either way, but the cost is not. A bust forfeits every dart left in your hand, so busting with your first dart hands back three darts and busting with your third hands back one.
Over a match this is a real difference, and it is the reason serious scorekeeping records which dart the bust happened on. A player who busts early repeatedly is misreading their leave; a player who busts on the last dart is usually just missing a double.
Worked examples
Three visits from 64, showing all three outcomes.
| Darts | Running | Outcome |
|---|---|---|
| T16, D8 | 64 → 16 → 0 | Checkout in two darts |
| T16, S16 | 64 → 16 → 0 | Bust — zero on a single |
| T16, S15 | 64 → 16 → 1 | Bust — left 1 |
Note that the correct route on 64 is T16D8, which is exactly the first row. It is the standard finish precisely because a missed treble 16 into the single still leaves 48, and a missed double 8 into the single leaves 8, which is double 4.
The out-rule variants
| Rule | Finishes with | Where you see it |
|---|---|---|
| Double out | Double or inner bull | Leagues, PDC, WDF, standard 501 |
| Straight out | Any segment | Casual and pub play |
| Master out | Double, treble or inner bull | Some US leagues, soft tip |
The out rule changes the whole shape of the endgame. Under straight out there are no bogey numbers at all, and finishes get much shorter — 159 becomes T20, T20, T13. Agree the rule before the first dart, not after a disputed finish.
Every route on the checkout chart assumes double out, because that is what leagues and televised darts use.
