501 Darts Rules: How to Play X01, Double-Out and Win a Leg
In 501 darts both players start on 501, throw three darts per turn, and subtract the total scored from their remaining number. The first to reach exactly zero wins the leg, but the final dart must land in a double (a double-ring segment or the 50 bullseye). Going below zero, landing on exactly 1, or hitting zero on a non-double is a bust: the turn is voided and your score returns to where it was before that turn.
That is the whole game in one paragraph. The rest of this guide fills in the details every new player needs: how a turn works, the exact bust rules, how legs and sets are structured, how 301 and 701 differ, and a worked leg you can follow dart by dart. These rules are the standard X01 format used by the Professional Darts Corporation and the World Darts Federation, and they are the same rules you will see on a pub board.
The objective: race from 501 to exactly zero
501 is a subtraction game. You do not add points up to a target; you start with a fixed score and work it down. Both players (or both teams) begin on 501. Each turn you throw three darts, total what they score, and take that off your running number. A maximum turn of three treble 20s scores 180, the highest possible with three darts, which would drop you from 501 to 321 in one visit.
The first player to bring their score down to precisely zero, with a legal finishing dart, wins the leg. You cannot overshoot: there is no such thing as finishing on minus 4. This is what makes the closing stage of a leg the hardest part, and it is where most beginners lose legs they were winning.
How a turn (a "visit") works
A single turn at the line, called a visit to the oche, is three darts. You throw all three (unless you check out earlier), then your opponent throws their three. The oche is the throwing line, set 2.37 m (7 ft 9.25 in) from the face of the board. Standard scoring on the 20-segment board is:
- Single: the large outer or inner area of a number, worth its face value (a single 20 is 20).
- Double: the thin outer ring, worth twice the number (double 20 is 40). The maximum double is double 20 at 40.
- Treble (also called triple): the thin inner ring, worth three times the number (treble 20 is 60, the highest single-dart score).
- Bullseye: the green outer bull scores 25; the red inner bull scores 50 and counts as a double for finishing.
Whatever the three darts total gets subtracted. If a dart bounces out or misses the board entirely, it scores nothing and is not re-thrown.
The double-out rule: how you actually win
Reaching zero is not enough on its own. In standard 501 you must finish on a double: the dart that takes you to exactly zero has to land in a double segment or the inner bullseye (which counts as double 25). This is the single rule that catches out new players, and it is non-negotiable in PDC, WDF and league play.
Examples of legal finishes:
- You have 40 left: hit double 20 and the leg is yours in one dart.
- You have 36 left: hit double 18.
- You have 50 left: hit the bullseye, which counts as a double.
- You have 32 left (a favourite): aim for double 16; miss into single 16 and you leave 16, still an even number you can take out with double 8.
If you have an odd or awkward number left, you use your earlier darts in the visit to set up a double. With 45 remaining you might throw single 5 to leave 40, then double 20. With 40 you go straight for double 20. Leaving yourself a clean even double is the heart of good X01 play, which is why a separate double-out and best-doubles-to-leave guide exists.
The two things beginners get wrong
New players lose legs to two specific mistakes: the running subtraction (losing track of what they have left) and the legal double finish (throwing at the wrong segment to close). The Darts Scorekeeper app removes both. It does the subtraction after every dart and only ever suggests finishes that legally close on a double, so you learn the format correctly by playing it correctly, not by memorising it cold.
Get Darts Scorekeeper on the App StoreThe bust rule, in full
A bust ends your turn immediately and resets your score to whatever it was at the start of that visit, with no points credited for the busted turn. Per the standard rules of the sport, you bust if a throw:
- takes your score below zero (you scored more than you had left), or
- leaves you on exactly 1 (which cannot be finished on a double), or
- reaches zero but the last dart was not a double (or bull).
A worked example: you have 32 left and need double 16. You aim for double 16 but hit treble 16 instead, scoring 48. That is more than 32, so you bust: no points, and your next visit starts from 32 again. Crucially, a bust voids the whole visit, not just the offending dart, and it does not end the leg. Play simply passes to your opponent and you carry on from your pre-turn score next time.
There is a stricter variant some venues use, the "northern bust," where your score reverts only to before the offending dart rather than the whole visit. The standard PDC and WDF rule is the full-visit reset above; if you are playing socially, agree which one you are using before you start.
Legs and sets: how a match is won
One complete game of 501, from 501 down to a double-out finish, is a leg. A match is decided by winning a set number of legs:
- Best of legs is the common format: "first to 3 legs" or "best of 5 legs" means the first player to win 3 legs takes the match. Most pub and league matches work this way.
- Sets add a layer for bigger events: a set is itself won by taking a number of legs (often best of 5 legs, so first to 3 legs wins the set), and the match is best of a number of sets. The PDC World Championship, for example, is contested in sets.
Players usually alternate who throws first each leg, since the player who throws first has a small advantage (they reach a finish one visit sooner). Whoever wins the bullseye throw at the very start of the match typically chooses to throw first.
301 vs 501 vs 701: the X01 family
"X01" is the umbrella name for every game in this family, where the X is the leading digit of the starting score. The rules of subtraction, busting and double-out are identical; only the starting number changes.
| Game | Start | Typical use | Common entry rule |
|---|---|---|---|
| 301 | 301 | Quick singles games, warm-ups | Often double-in, double-out |
| 501 | 501 | Standard pub and pro format | Double-out (straight start) |
| 701 | 701 | Doubles and team play | Double-out (straight start) |
301 is short, so a single hot or cold turn swings it heavily, which is why it is often played double-in (you must hit a double before any of your scoring counts) to lengthen it. 501 is the sweet spot: long enough to reward consistency, short enough to finish quickly, which is why it is the default everywhere. 701 stretches things out for teams and is popular in doubles formats. The Darts Scorekeeper app plays all three for free for up to two players, with custom starting scores available on Pro.
A worked leg, dart by dart
Here is a single 501 leg for one player, showing the running subtraction and the double-out finish.
| Visit | Darts thrown | Scored | Left |
|---|---|---|---|
| 1 | T20, T20, T20 | 180 | 321 |
| 2 | T20, T20, T19 | 177 | 144 |
| 3 | T20, S20, T8 | 104 | 40 |
| 4 | D20 | 40 | 0 (win) |
In visit 3 the player has 144 left and wants to leave a clean double. Treble 20 (60) leaves 84, single 20 (20) leaves 64, then treble 8 (24) leaves 40, the textbook two-dart finish. Visit 4 is a single dart: double 20 for 40, and the leg is won. That final double is the only thing that legally ends the game, which is exactly the rule the app enforces and suggests for you, so you never throw at the wrong target on a winnable visit.
Note: 170 (T20, T20, bullseye) is the highest possible checkout in three darts. Anything from 2 to 170 that ends on a double is reachable; numbers like 169, 168, 166, 165, 163, 162 and 159 are not checkoutable in three darts. A full printable checkout chart from 2 to 170 covers every finish.
Learn 501 by playing it right
The fastest way to internalise these rules is to play a real leg with the scoring handled correctly. The Darts Scorekeeper app does the running subtraction after every dart, flags busts the instant they happen, and only suggests finishes that legally close on a double, so the format teaches itself as you throw. It is free for 301, 501 and 701 with up to two players, no account and no ads.
Download Darts Scorekeeper on the App Store
Frequently asked questions
What are the basic rules of 501 darts?
Both players start on 501, throw three darts per turn, and subtract the total scored from their remaining number. The first to reach exactly zero wins the leg, but the last dart must land in a double (a double segment or the 50 bullseye). Going below zero, landing on 1, or reaching zero on a non-double is a bust, which voids the turn.
Do you have to start on a double in 501?
No. Standard 501 is double-out only: you score from your first dart and only the finish must be a double. A few elite events such as the PDC World Grand Prix use double-in, double-out, but that is the exception, not the normal pub or league rule.
Why is leaving 1 a bust?
Because 1 cannot be finished on a double. The lowest legal double-out is double 1, which is 2. Drop to 1 and you have no legal dart to throw, so the rules treat it as a bust and reset your score to the start of the turn. Aim to leave an even number you can halve into a double.
How are legs and sets different?
A leg is one full game of 501 to a double-out finish. A match is usually best of a number of legs (for example first to 3). Bigger events add sets: a set is won by taking a number of legs, and the match is best of a number of sets. Casual play is decided by legs alone.
What is the difference between 301, 501 and 701?
They are the same game (X01) with a different starting score. 301 is the shortest and is often played double-in, 501 is the standard format, and 701 is longer and common in team play. Subtraction, busting and the double-out finish are identical across all three.