Draw by Agreement
A draw by agreement occurs when both players agree to end the game without announcing a winner.
Insufficient Material
A draw due to insufficient material occurs when neither side has the correct pieces to checkmate the other. This happens when any of the following sets are the only pieces left in play:
1) a king on one side and a king on the other side
2) a king on one side and a king and a bishop on the other side
3) a king on one side and a king and a knight on the other side
Stalemate
According to the Borders Chess Club, a draw by stalemate occurs "if a player has no legal moves on his turn, but is not in check."
End of Time
In competitive chess, games are timed. If both players run out of time on their chess clocks, the game is a draw.
Threefold Repetition of Postion
When a player moves a piece into the same position three times in a row, the game ends in a draw by threefold repetition of position.
The Fifty Move Rule
Players have an option to call a game a draw if one or both players are able to make 50 moves without capturing a piece or moving a pawn.