There are a number of board games that have had boards (and usually playing pieces) made from LEGO. At right is an example of a Ludo (a game in the Cross and Circle game family) board represented that way.
A popular board game to be reproduced in LEGO is chess, often with two competing factions within a theme, such as pirates and soldiers or two factions of knights. An official Knight's Kingdom Chess Set was produced followed quickly by a Vikings version when that Theme was introduced.
Some AFOLs have created board games based on themes themes such as Star Wars,Raiders,etc.