X01 is the standard family of competitive darts games (501, 301, and 701). Each player starts at the chosen score and races to reach exactly zero, finishing with a double. This guide covers equipment, the scoring system, double-out and bust rules, checkout strategy, and how the 9Darter app tracks everything automatically.
What Is X01?
X01 is the cornerstone of competitive darts. The name refers to a family of games where the starting score ends in "01": the most popular are 501, 301, and 701. Every player (or team) starts at the chosen score and races to reach exactly zero. The first to do so wins the leg.
X01 is played at every level, from pub leagues to the PDC World Championship. Mastering its rules is the foundation of any dart player's journey.
What do you need to play X01?
You need a standard dartboard (bristle or electronic) hung with the bullseye at 1.73 m from the floor, and a throwing line (oche) at 2.37 m from the face of the board. Each player uses three darts per turn. In 9Darter, the app handles all the setup: just select your game type (301, 501 or 701) and number of players, and scoring begins automatically.
How do you play X01?
- Set up the board. Hang the dartboard with the bullseye at 1.73 m from the floor and the oche at 2.37 m from the board face.
- Choose your starting score. Pick 301, 501 or 701. 501 is the competitive standard; all players begin at the same score.
- Throw three darts per turn and subtract. Players alternate turns. On each turn throw all three darts and subtract the total from your running score. Outer ring = double, inner ring = triple, inner bull = 50, outer bull = 25. There is no minimum score per turn.
- Avoid busting. If you score more than your remaining total, reduce it to exactly 1, or reach zero without a double, your turn is a bust and the score reverts to its value at the start of that turn.
- Finish on a double. Your final dart must land in the narrow outer double ring (or bullseye, which counts as double 25) to bring your score to exactly zero and win the leg.
What is the double-out rule in X01?
The most important rule in X01: you must finish on a double (or the bullseye, which counts as a double 25). This means your final dart must land in the narrow outer ring, exactly halving the segment's face value, to bring your score to zero. For example, if you have 32 remaining, you need double 16. If you have 50 remaining, you can finish on the bullseye.
This rule is what makes X01 tactical: planning your checkout route is as important as throwing accurately.
What is the bust rule in X01?
If you score more than your remaining total, or reduce it to exactly 1 (leaving no valid double finish), or reach zero without finishing on a double, you bust. Your score resets to what it was at the start of that turn, and play passes to the next player. Busting on a critical turn can cost you a leg, making risk management essential.
What is the difference between straight-out and double-out?
Most professional and competitive play uses the double-out rule. Some casual and beginner formats allow straight-out, where any dart that brings your score to exactly zero wins the leg, regardless of segment type. Always agree on the format before starting.
X01 Variants at a Glance
| Variant | Starting Score | Typical Context | Approx. Leg Duration |
|---|---|---|---|
| 301 | 301 | Quick games, local leagues, pub play | ~5–10 min |
| 501 | 501 | Competitive standard (PDC / WDF) | ~15–20 min |
| 701 | 701 | Team play or extended training sessions | ~25–35 min |
What are the best X01 strategy tips?
- Go for treble 20. In 501 and 701, aim for T20 (60 points) to reduce your score fast. It is the highest-scoring single target on the board.
- Know your checkout routes. Common finishes: 170 (T20 T20 Bull), 160 (T20 T20 D20), 121 (T20 T11 D20). Memorising the top 40 checkouts removes hesitation under pressure.
- Set up your finish. As you approach low scores, aim to leave yourself on an even number that maps to a clean double. If you have 37, aim to hit a single 1 to leave 36 (D18), rather than risking the double 19 directly.
Play X01 with 9Darter
9Darter automatically tracks your score, suggests checkout routes as you get close to finishing, and records your best games and average scores. Whether you're playing 301 for a quick solo practice or 501 with friends, the app keeps everything accurate so you can focus on your throw.