Baseball rules in five minutes
Rules baseline: Major League Baseball's 2026 Official Baseball Rules and current MLB competition procedures. NCAA, NFHS, Little League, international, and local baseball modify important details.
- Objective: score more runs by batting the ball and safely touching first, second, third, and home before the defence records enough outs.
- Players, field, and equipment: MLB uses nine players in the field on a diamond with 90-foot basepaths; bats, balls, gloves, helmets, bases, and uniforms must meet the applicable code.
- How play begins: the visiting team bats first, and each live-ball sequence begins when the pitcher legally delivers or otherwise puts the ball in play.
- Possession and turns: teams alternate offence and defence after three outs; batters hit in lineup order and runners may advance at their own risk unless a rule awards bases.
- Scoring: one run scores when a runner legally touches all four bases in order before the third out, subject to timing-play, force-out, appeal, and preceding-runner rules.
- Length and winner: an MLB game is normally nine innings; extra innings continue until one team leads after a completed inning, with current regular-season MLB runner procedures applying.
- Main violations: balks, interference, obstruction, illegal pitches, batting out of order, running-lane interference, and equipment or pace-of-play breaches create outs, bases, balls, strikes, or warnings.
- Restarts and penalties: play resumes with the ball made live after dead balls, substitutions, base awards, foul balls, and umpire time; some violations remain live until action ends.
- Competition differences: designated hitters, re-entry, pitch clocks, mound visits, mercy rules, base sizes, extra innings, replay, and pitching limits vary sharply by level.
- Go deeper: start with force plays, obstruction and interference, balks, appeals, and the full list below.