Learn Raumschach

Forget the flat 8×8 board. Raumschach is played on a cube of 125 cells arranged as five 5×5 boards stacked vertically. Each board is a Level, labeled A (bottom) through E (top). Pieces move between levels just as naturally as they move across the usual ranks and files.

The diagram below shows the five levels as they appear on screen when you play the online game — levels spread out flat for readability. In your mind, imagine stacking them one atop another like floors of a building, or like decks of a starship.

Every cell has a three-part name: Level · File · Rank. Level is a capital letter A–E, file is a lowercase letter a–e, and rank is a digit 1–5. The center of the board is Cc3.

Examples: Aa1 is the bottom-left corner of Level A (White’s back corner). Ee5 is the top-right corner of Level E (Black’s back corner). When White’s King starts on Ac1, that means Level A, file c, rank 1 — the center of White’s back row.

White occupies Levels A and B; Black occupies Levels D and E. Level C begins empty — a vast no-man’s-land in the middle of the cube. Each side has the usual pieces plus two Unicorns (explained in Step 5).

Every familiar piece gains a new axis of freedom. The key insight from Dickins is elegant:

• The Rook moves through cell faces — the six flat sides of a cube. This gives it three axes: along files, along ranks, and up/down through levels.
• The Bishop moves through cell edges — every edge is shared by exactly two faces, giving 2D diagonals, including diagonals that climb or descend through levels.
• The Unicorn moves through cell corners — each corner touches three faces simultaneously, giving purely 3D diagonal moves.
• The Queen combines all three: Rook + Bishop + Unicorn.
• The King moves one step in any Queen direction.
• The Knight uses the classic (1-2) leap on any two of the three axes.

The Unicorn is the only piece unique to Raumschach. Dickins describes it as the “three-dimensional Bishop”: where the Bishop moves through cell edges (changing two coordinates at once), the Unicorn moves through cell corners, changing all three coordinates simultaneously.

A Unicorn beginning on Aa1 can travel the long space diagonal to Bb2, Cc3, Dd4, Ee5 — a path that cuts straight through the heart of the cube. Note that this path is the only diagonal through Cc3 that a Unicorn can follow; a Unicorn placed anywhere else can never reach Cc3 at all, because the Unicorn’s parity (level + file + rank, mod 2) is invariant throughout its life. This also means no Unicorn could ever stand on Cc3 unless it began on the diagonal from Aa1 — which is precisely why the Unicorn illustration in Step 4 uses that square only as a geometric reference, not a legal starting position.

Each player begins with two Unicorns. White’s are on Bb1 and Be1. Black’s are on Da5 and Dd5 — note these are not the mirror of White’s files; the asymmetry is correct by the original rules. In diagrams, the Unicorn is conventionally illustrated as an upside-down Knight symbol. Maack’s own physical set used a modified Knight piece — a Knight figure with a horn attached to its head, standing upright — to distinguish it from the ordinary Knight.

Pawns in Raumschach follow an elegant rule: they move rookwise (one step along a rank or upward through levels) but capture bishopwise (one step diagonally), always advancing toward their promotion rank.

White Pawns promote on the 5^th rank of Level E. Black Pawns promote on the 1^st rank of Level A. There is no double-step first move and thus no en passant capture, per Thomas Rayner Dawson’s authoritative descriptions.

A White Pawn on Cc3 can move to Cc4 (rank advance) or Dc3 (level advance), and capture on Cb4, Cd4, Db3, Dc4, or Dd3 — five possible capture squares.

Check, checkmate, stalemate, and draws by repetition or the 50-move rule all work exactly as in standard chess. The only difference is that the King can be attacked from far more directions — including from above and below — so exposing your King is even more dangerous.

Because the board is so large (125 cells), endgames tend to be longer. Rook-and-King versus lone King is a standard win. The Queen is enormously powerful given its combined Unicorn capability. The Unicorn alone cannot deliver checkmate but is a potent attacking piece in combination.

Promoted Pawns may become any piece — Queen, Rook, Bishop, Unicorn, or Knight.

The IRF hosts a free browser-based Raumschach game at raumschach.org/raumschach.html. No download, no account, no fee. The interface shows all five levels side by side — click a piece to see its legal moves highlighted, then click the destination square.

Start by playing a few games against yourself, focusing on one piece type at a time to build intuition for the 3D geometry. The Rook is the most intuitive — start there. Then experiment with the Unicorn; its geometry is surprising and beautiful.

The International Raumschach Federation is open to all — no fees, no barriers. The IRF organizes Live Remote Play events where members play each other in real time, typically over a shared screen or video call while using the online board. No special software is needed beyond a browser.

To participate: contact the IRF via the Contact page. Read the IRF Charter — membership requires only agreement with the federation’s principles of open, non-commercial, rigorous play. Tournament pairings and results are published at Ratings & Results.

All published theory, rulings, and game records are freely available. The IRF maintains the canonical rule set grounded in Maack’s 1907 originals and the authoritative Thomas Rayner Dawson (1889–1951) descriptions of 1926. Further reading: Dickins (1969/71), Maack’s Game Rules.