Baseball around the world is played under three major rules codes, which differ only slightly. The North American professional leagues and many amateur leagues use the Official Baseball Rules, which are published to the public by The Sporting News; U.S. collegiate and college-age play is often covered by the baseball rulebook of the NCAA; and U.S. high school and high school-age baseball is governed by the NFHS rules. IBAF international teams, most leagues outside North America, and youth baseball organizations such as Little League, PONY League , and Cal Ripken League all play under slightly modified versions of the Official Baseball Rules.

Unlike many other sports, the Official Baseball Rules have remained largely static during the modernization of the game. Many baseball players, fans, and administrators view the rules and traditions of professional baseball as time-tested and nearly sacrosanct; even the designated hitter rule, first introduced to play over 30 years ago in 1973, is still subject to lively debate and has been adopted by only one of the two American major leagues—though almost all other leagues around the world have adopted it. In fact, NFHS rules allow the designated hitter to bat for any position. In contrast to the Official Baseball Rules, the NFHS is continually refining and updating its rule book to meet the needs of the United States high school game.

In Japan, if a regular-season game is tied after nine innings, only three extra innings may be played. The accepted codes of ettiquite also differ in Japanese baseball, though these are not written in official rules.

Other major differences often center around additional safety rules. Most amateur leagues prohibit malicious contact by runners, are stricter on interference calls, and require double-earflap helmets.

For an overview of the rules themselves, see Main article: baseball, the baseball rules category below, or each individual rule book.

External Links

• Official site for the Official Baseball Rules
• NFHS rulebook ordering site
• Official NCAA rules (pdf)