~1.84 × 10¹⁹ Starting Positions: The Immense Universe of EXPTIME CHESS

Imagine you sit down at a chessboard. But instead of familiar pieces, you face emptiness. Your opponent sits across from you, and the first question is not “what opening to choose?”, but “what world will we create now?”.

This is no exaggeration. This is EXPTIME CHESS, and its main feature lies in that silent pause that precedes every battle. You do not begin to play. You begin to create worlds.

White places 8 pieces on their first rank. Black is obliged to mirror them on their eighth rank. Black adds their 8 pieces — and White immediately returns their reflection. Row by row, in perfect symmetry, the two of you weave a dense, intricate tapestry of 64 pieces on the board.

This is not preparation for the game. This is a zero-level game, a meta-battle where you define the initial conditions for a cascade of fatal exceptions. And the room for maneuver here is not just large — it is astronomical.

How many such starting patterns exist?

The new data shows there are approximately 1.84 × 10^19 possibilities. That’s 18.4 quintillion unique starting positions.

To grasp the scale: in Chess960 (Fischer Random Chess), famous for its variety, there are only 960 starting positions. EXPTIME CHESS offers a universe of possibilities that is 19 quintillion times vaster. You are not simply choosing an opening. You are constructing the very fabric of a reality in which the conflict will unfold. Each of these ~18.4 quintillion positions is a separate logical universe with its fate already encoded within it.

Key Clarifications

Symmetry: Numerous positions are color- or axis-symmetrical. However, the rules treat them as unique because the players (White and Black) make their setup choices in sequence.

Equivalence: Certain arrangements could result in strategically isomorphic play, yet they are formally defined as separate starting positions.

And when the board is finally filled, the second, visible part of the game begins. But now your every move is not an attack, but the forced erasure of one cell of this mirrored tapestry you have just woven. The symmetry begins to unravel, and which thread you pull first determines whose picture will ultimately turn to void.

Your goal is not to destroy the enemy's army. Your goal is to force the opponent, on their own turn, to erase their last piece. Every step you take is a sacrifice. You are not gaining material advantage — you are transmuting your own substance into a logical impulse that changes the rules of the field. And this entire intricate chain of sacrifices grows from that single choice you made when placing the first 8 pieces into the void.

This is the genius of the game. It is divided into two acts, each overturning the very notion of strategy.

Act I: The Architect. You are the master builder, choosing one world out of four quadrillion possibilities.

Act II: The Protocol Executor. You are the executor, obliged to run fatal procedures in the trap of your own algorithm, where every call diminishes your own computational base.

EXPTIME CHESS is not a chess variant. It is an inquiry into the very nature of conflict, where the decisive battle occurs not in the thick of the fray, but in silence, at the moment of initializing the 8x8 matrix. This is a game for those ready to think one step ahead — no, even more. 18.4 quintillion steps ahead.