Copyright (c) ? Christian Freeling

This game is played on a 7x7 square board with the following setup:

TURN - On each turn, each player moves one of his pieces:
The King may move to the next (orthogonally or diagonally) empty cell.
When attacked, the King can only move to an adjacent empty cell.
A King cannot move inside the non-restricted moving range of the enemy King (i.e., it's forbidden to move to a cell where the opposite King might move next turn if it was not attacked).
Kings can capture by replacement.
The warrior may move to the next (orthogonally or diagonally) empty cell (like the King).
However, it may continue to the second next empty cell (in the same direction) placing a neutral piece on the first cell.
Warriors can capture by replacement opponent King (they cannot capture warriors).
If a player cannot move, he passes his turn.
GOAL - A player wins by checkmating the enemy King.
An example [from here]

The Black warrior is attacking the King. Because of that, the King can only move to one of the green dots. The red dots indicate positions that were possible to move if the King was not attacked.

The King cannot capture the warrior because they are not adjacent.

There's also a hexagonal variant HexShakti.