The only difference between Improved Chess and regular chess is the additional movement directions of the Pawn. The improved Pawn, provided that it (1) has reached the other half of the board, and (2) the forward movement is blocked, has the additional moves of a knight, but only in two forward directions: east-north-east, and west-north-west, and only to empty squares. There are no additional capture moves.

There are two alternative blockage rules:
(1) the pawn must be blocked by an enemy piece/pawn.
(2) the pawn can also be blocked by a friendly piece/pawn to acquire the oblique move.

Middlegame and endgame are more aggressive while improved Pawns are not easy to block. In Improved Chess, drawish endgames will occur less often. Many theoretical endgames that have hitherto been drawn are now won. In an alternative variant the pawn must reach beyond the fifth rank to get the extra move capability. This will hardly affect opening theory at all. The variant where the pawn must reach beyond the fourth rank could possibly affect some variants, like Modern Benoni.

This method is a surprisingly simple way of introducing extra complexity. The technical and theoretical nature of today's computerized chess, calls for a change toward higher complexity. Comparatively, in orthodox chess a pawn is easy to block. This creates the marked drawishness of practical endgames. Therefore, most chessplayers prefer to keep the queen on the board, until they have created an advantage.

Three variants

The new pawn is not overly wild. In order to get the extra movement capability, the pawn must be blocked (by an enemy piece/pawn)...

(1) anywhere on the far side
(2) anywhere beyond the fifth rank
(3) on the seventh rank.

Note! As an alternative, the pawn may move obliquely also when blocked by a friendly piece ("friendly blockage" variants).

An alternative way of playing, called Crab Chess, is to allow the oblique Pawn moves whereever a Pawn is blocked.