Tridimensional chess is classic chess literally with a new dimension. Imagine a standard chessboard cut it into 4x4 quarter-boards. Arrange two of these end to end forming a 4x8 rectangle, then stack a third over the rectangle's center (leaving two rows uncovered on either end). Quarter the remaining quarter-board into 2x2 attack boards and place one at each corner such that it overlaps only the corner square, creating an overall but unfilled outline of a 6x10 rectangle.

Initially then the playing field expands by three squares for each attack board (12 squares) for a maximum total of 44 squares - some overlapped, some not - in 2D space. (The term "cell" henceforth designates a square with potentially more than one dimension.)

Pieces setup according to the Technical Manual and move as usual. They may "land" at any unoccupied dimension inside a multi-dimensional cell; any dimension occupied by an enemy can be captured by the attacker assuming its dimension. Pieces with continuous motion are obliged to stop at a cell if it is occupied (friend or foe) at any dimension - this is known as the "must-stop" rule. Good play exploits such dynamic, many-dimensioned combinations of pieces. Discovering new dimensional combinations - even if only tactically - makes Parmen's computational play so tough!

The attack boards move only if empty or piloted by a sole piece; this counts as the player's move. Attack boards move two or four squares along the periphery, keeping their checkerboard scheme aligned with the fixed boards below. Of the five major differences between the Standard and Tournament rulesets, four are easy and relate to attack boards:

First, in Standard an attack board pilot can only be a pawn.

Second, in Tournament attack boards can move laterally across the board - i.e., no forward translation.

Third, in Tournament rooks and queens may "jump" across non-contiguous squares.

Fourth, in Tournament attack boards may only move forward or laterally - never "backwards."

The fifth, more troublesome difference is that the "must-stop" rule is replaced in Standard by allowing continuous pieces to move through any occupied cell so long as their destination is "higher" than that cell. This rule is not-well formulated and complicates the game by many orders of unnecessary magnitude. Beginners are urged to start with the Tournament ruleset for this reason.

Multi-dimensional chess begins to converge as its flatland predecessor did over the last millenium. Larger, more complex variants may introduce a "fog of war" but give me close quarters combat anytime. Tridimensional Chess is the tag-team pit-fight of the chess variant world.