A goal may not be scored directly from a throw-in as stated in FIFA, Laws of the Game. Throw-ins are usually thrown to a player.
Laws of the Game
The Laws of the Game are the codified rules that help define association football. These rules were first played by members of the Cambridge University Football Club on Parker's Piece, Cambridge in 1848, and adopted by the Football Association in October, 26, 1863. "They embrace the true principles of the game, with the greatest simplicity" (E. C. Morley, F.A. Hon. Sec. 1863) These laws are written and maintained by the International Football Association Board and published by the sport's governing body FIFA. The laws mention the number of players a team should have, the game length, the size of the field and ball, the type and nature of fouls that referees may penalize, the frequently misinterpreted offside law, and many other laws that define the sport.
The current Laws of the Game (LotG) consist of seventeen individual laws, each law containing several rules and directions: Throw-in