Not sure what to play?
Pick a vibe or category. Roll. Re-roll until something clicks.
Rolling for: 🎲 Random
Free Game Tools
No signup. Use them mid-game on any device.
Settle It Instantly
Real rule disputes — answered with official sources.
“How does scoring criteria work in Boxing (IBF)?”
IBF judges evaluate each round based on four criteria, weighted in the following order of importance: Clean, Effectiv...
Boxing (IBF) · #scoringRead full rule →“What is protective equipment in Softball?”
Double-ear-flap batting helmets with face masks/guards are mandatory for all batters, on-deck batters, and base runne...
Softball · #safety-considerationsRead full rule →“What is the ball in Beach Volleyball?”
Circumference: 66–68 cm (26–26.8 in) — slightly larger than the indoor ball (65–67 cm); Weight: 260–280 g (9.2–9.9 oz...
Beach Volleyball · #equipmentRead full rule →“What is band-aid tag in Tag?”
A variant designed for continuous play without role-switching pauses.
Tag · #rules-of-playRead full rule →Hot Rules Right Now
Most-viewed official rulebooks this week
Featured Sports
See all →
Fall Sports
Fall-season competitive sports
Did You Know?
10-Point Must System
Same rule. Different sports. Different answers.
WBA
The 10-Point Must System is the standard scoring system for all WBA bouts. Under this system: The winner of each round receives 10 points; The loser of each round receives 9 points or fewer; An even round is scored 10-10 (though even rounds should be rare)
PowerSlap
Matches are scored on the 10-Point Must System. Open scoring may be used at the Promoter's election, in consultation with the Executive Director and/or Commission.
Gaining Traction
Community sports picking up momentum right now
Recently Updated Rules
Official rulebooks with fresh changes
GAA
3 rules updated · 9d ago
Latest: Section 6: Scoring
WCT
6 rules updated · 14d ago
Latest: Section 8: Safety Considerations
ISU
29 rules updated · 16d ago
Latest: 8.4 Heat Size Limits
International Padel Federation
4 rules updated · 16d ago
Latest: Net and Wall Violations
World Aquatics
9 rules updated · 16d ago
Latest: Section 8: Safety Considerations
World Lacrosse
9 rules updated · 16d ago
Latest: Section 8: Safety Considerations
No More Arguing
Search the Rule
“Is a double dribble legal?” “Can you bounce in beer pong?”
Get the Verdict
Cited rule number and source. No opinions — just the answer.
Send the Proof
Share a direct link. One tap — argument over.
No more guessing. No more debates.
Every official sport started somewhere
How a Sport Becomes Official
Open Source Sports gives new sports a visible path forward.
Most sports never reach this stage. Yours can.
This is the path every custom sport follows on Open Source Sports.
What are you here for?
Two tracks, one platform. Pick your path.
Official Sports
Trusted rules from real governing bodies.
- ✓ Verified rulebooks, cited with rule numbers
- ✓ League comparisons and seasonal updates
- ✓ Instant verdicts for common disputes
NFL, FIFA, NBA, UFC, and 218 more
Settle a RuleCustom Sports
Turn your idea into a recognized sport.
- ✓ Create your own sport from scratch
- ✓ Community voting and rule proposals
- ✓ Path to endorsement and official status
Beer pong, backyard games, and your next idea
Create a SportSport of the Day
NCAA
Alpine Skiing
NCAA Alpine Skiing is the collegiate variant of alpine skiing contested by NCAA Division I, II, and III institutions in the winter semester. NCAA Skiing combines Alpine Skiing (slalom + giant slalom only — speed events not contested at NCAA level due to course/safety constraints) and Nordic Skiin...
Explore by Category
Who Decides the Rules
Sourced from 112 governing bodies worldwide.
Help Keep the Rulebook Open
OpenSourceSports stays useful when people improve the rules, suggest missing sports, and support the tools that keep play moving.