Another way of getting a draw is THE FORTRESS.

Here's a fine example where even a famous chessplayer as Tarrasch failed to see the Fortress.

This is from Chigorin-Tarrasch, Nuremburg 1896 where Tarrasch  resigned.  Tarrasch had concluded that after 1.gxf6 gxf6 2.h5 h6 he'd lose the f-pawn and the game. So he resigned.

What Tarrasch failed to see was that he could have escaped with a draw by going into a fortress as follows:

Another example is this one from Kobaldze-Tseretell, Tibilisi, 1970. Black from the looks of it is doomed. On 1..Na8, the N gets picked off with 2.Bd7 and 3.Bc6.

Watch how Black gets a draw.