---
title: "Los Alamos"
slug: "los-alamos"
board: "6×6"
players: "2"
parent: "moddable-chess"
order: 31
win: "Checkmate"
special: "First computer chess (1956). 6x6 board, no Bishops, no castling."
---

## Los Alamos

The first chess variant ever played by a computer (1956, MANIAC I at Los Alamos National Laboratory). A 6×6 board with no Bishops and no castling.


{{svg:los-alamos-board.svg "Los Alamos Chess — starting position (6×6)"}}

### Setup

**Board:** 6×6 (six files, six ranks).

**Setup (FEN):** `rnqknr/pppppp/6/6/PPPPPP/RNQKNR`

Each side: Rook, Knight, Queen, King, Knight, Rook (+ 6 pawns). No Bishops.

### Rules

- Standard chess movement for all pieces (Rooks, Knights, Queen, King, Pawns).
- No Bishops exist in this variant.
- No castling.
- Pawns move one square forward only (no double-step from starting rank).
- No en passant (since there's no double-step).
- Pawns promote on the far rank to Queen, Rook, or Knight (no Bishop promotion since Bishops don't exist).

### Win Condition

Checkmate or stalemate the opponent (stalemate is a loss in Los Alamos rules).

### Strategy

Without Bishops, there are no long-range diagonal attackers. Knights become relatively more powerful since the board is smaller (fewer moves to cross). The Queen is overwhelmingly strong on a 6×6 board — trade it only for the opposing Queen. Games are short and tactical. The smaller board means Kings have fewer escape squares, making endgame mating patterns easier.

### Attribution

Paul Stein and Mark Wells, Los Alamos National Laboratory, 1956. Public domain.