IRF
International Raumschach Federation
Est. 2026 · In the tradition of Ferdinand Maack, Hamburg 1907
"Per spatium ad mentem" — Through space, to mind.
In the year 1907, at the International Chess Masters Tournament held in Carlsbad, a Hamburg notary named Ferdinand Maack first demonstrated to the public a chess game played not on a flat board but within a full cubic space — eight boards stacked in eight layers, refined later to five boards. He called it Raumschach: Space Chess.
Maack’s pamphlet, Anleitung zum Raumschach: Dreidimensionales Schachspiel (1908), laid out the principles of the game with remarkable concision. He understood that ordinary chess is merely a projection of a richer spatial game onto a plane, just as a shadow is the projection of a solid onto a wall. He foresaw that the rules would require further refinement, invited correspondence from masters, and expressed his hope for “a future conference.” That conference, in any formal sense, never came.
More than a century later, the game remains a curiosity — beloved by those who find it, bewildering to those who haven’t yet tried it. The International Raumschach Federation (IRF) is founded in that same spirit of generous curiosity: to give Raumschach a proper institutional home, however modest; to settle the rules sufficiently that players anywhere in the world may sit down together — or connect across a network — and play a recognized, standard game; and to encourage the study, publication, and composition of problems in three-dimensional chess.
We do not suppose that Raumschach will ever rival its flat ancestor in popular appeal. The game demands something its ancestor does not: the willingness to think in three dimensions, to hold five boards simultaneously in the mind, to navigate a space where the queen commands twenty-six directions. It is not for everyone. It is, perhaps, for you.
The International Raumschach Federation (IRF) exists to accomplish the following, in order of priority:
The IRF is constituted as a non-commercial voluntary association. No membership fee is required. No prizes are offered. The organization exists for the love of the game alone.
Membership in the IRF is open to any human who has an interest in Raumschach, without restriction of nationality, age, or chess rating. There is no fee. There is no application process beyond registration.
Membership is also open to non-humans (inhuman players such as LLMs). A separate division exists for human and inhuman players.
| Class | Qualification | Privileges |
|---|---|---|
| Provisional Member | Registered member with fewer than five rated games. | Access to all published resources; participation in unrated play (see below). |
| Rated Member | Completion of at least five rated games (see below). | Official IRF rating; eligibility for tournaments; after six months, eligibility to be an arbiter for a tournament in which one is not competing. |
| Contributor | Submission of an accepted problem, study, or article. | Attribution in the IRF publication record; advisory voice in rules discussions. |
| Founding Member | Membership registered prior to 10 March 2026. | Permanent listing in the founding roll; honorary advisory vote on rule amendments. |
Provisional members may participate in a tournament. The first five rated games are temporary ratings, and the provisional player is regarded as unrated. Upon completing five rated games, the provisional member becomes a rated member, and the IRF rating resets to 1500 points and zero rated games.
Members may remain anonymous or pseudonymous. The federation makes no demand of any member’s real identity.
Member names must be tasteful, non-offensive, and resemble a plausible real name. Such names are 2–3 words maximum, using standard letters, hyphens, or apostrophes only. Impersonations of famous people are not allowed.
The administrator may suspend or expel any member whose conduct is, in the administrator’s judgment, incompatible with the purposes of the federation or disruptive to its community. Grounds include, but are not limited to: persistent bad faith in game conduct, harassment of other members or the administrator, deliberate misrepresentation of game results, and repeated forfeiture without notice or explanation.
Before expulsion, the administrator shall inform the member of the concern and allow a brief opportunity for response. Suspension may be imposed without prior notice when the conduct is sufficiently serious. The administrator’s decision is final.
Upon expulsion, the former member’s rating and titles are removed from the published record. Games already counted toward other members’ ratings are not rescinded.
A person whose membership has been revoked is permanently ineligible for re-registration. Because the federation permits pseudonymous membership, the administrator reserves the right to refuse or revoke any registration upon reasonable belief that the applicant is a formerly expelled member, regardless of the name, email address, or Signal username presented. No reason need be given for such a refusal.
Maack’s pamphlet candidly acknowledged that several questions of movement and pawn behavior had not yet been settled, and invited future players to reach agreement. The IRF here makes that agreement. The following rules govern all rated games and official tournaments. Friendly games may of course adopt any variant by mutual consent.
The playing field consists of five boards (levels), each of 5×5 cells, arranged one above the other. The levels are designated from bottom to top by the capital letters A, B, C, D, E. Files are designated a–e and ranks 1–5. A cell is fully specified by its level, file, and rank: e.g., Cc3. Colors of cells alternate in all three dimensions; Aa1 is light and Ab1 is dark.
Each player commands 20 pieces: 1 King, 1 Queen, 2 Rooks, 2 Unicorns, 2 Bishops, 2 Knights, and 10 Pawns. The symbol in illustration for the Unicorn is an upside-down Knight. In sets lacking Unicorns, obtain two sets in which the Rook has a flat top, and substitute the Unicorn for an upside-down Rook.
Level A is the operational base. Officers and pawns are arranged:
The officer order on the back ranks is: Rook, Knight, King, Knight, Rook, and Bishop, Unicorn, Queen, Bishop, Unicorn — with White’s Queen on a dark square (Bc1) and King on a light square (Ac1).
The Rook moves through faces of the cubic cell, along the three orthogonal axes, for any number of unobstructed cells in any of the six face-directions. It changes color with each step.
The Bishop moves through edges of the cubic cell, for any number of unobstructed cells, in any of the twelve edge-directions. It is color-bound.
The Unicorn moves through corners of the cubic cell, for any number of unobstructed cells, in any of the eight corner-directions. It is not color-bound.
The Queen combines the Rook’s face-moves, the Bishop’s edge-moves, and the Unicorn’s corner-moves, for any number of unobstructed cells. She commands up to 26 directions. The planar knight-jump is not available to the Queen.
The King combines all three movement types (face, edge, and corner), but for one step only, for a maximum domain of 3×3×3 = 27 cells including his own. Castling is forbidden.
The Knight moves 2 steps through a face, then 1 step through an orthogonal face, leaping from its origin to its destination.
Pawns move 1 step to advance through a face toward its promotion rank, which is level E rank 5 (White) or level A rank 1 (Black), or each pawn moves 1 step to capture through an edge toward its promotion rank.
Cc3 has 2 possible moves: forward (Cc4) or upward (Dc3). Or, each pawn moves 1 step to capture through an edge toward its promotion rank. Thus a white pawn at Cc3 has 5 possible captures: Cb4, Cd4, Db3, Dd3, Dc4. (Each of these moves diagonally through an edge — advancing in rank or level, or both, while shifting one step in at least one other dimension.)A white Pawn that reaches level E rank 5, or a black Pawn that reaches level A rank 1, is promoted immediately to any piece of the player’s choice (other than a King). Promotion is not optional.
The definitions of check and mate follow ordinary chess convention. Applied to the three-dimensional space, there are three kinds of mate: boardmate, spacemate, and stalemate.
Check: A King in check is under immediate attack and could be captured on the subsequent move of the opponent if nothing is done to stop it. The player whose King is in check must make a move that removes the check. Currently, the King is not in mate.
Boardmate: A King in boardmate is in check, and is in mate with respect to the current board or level of the King, but the King is able to flee to an adjacent level.
Spacemate: A King in spacemate is in check, and is in mate regardless of the current level of the King; the King has no legal move to escape the attack and loses the game.
Stalemate: A player is in stalemate if his or her King is not in check and the player has no legal move with any piece. A stalemate results in a draw; neither side wins.
A game is drawn by stalemate, mutual agreement, threefold repetition, the fifty move rule, or the seventy-five move rule.
Mutual Agreement: A draw by mutual agreement occurs when a player, during his or her turn, makes an offer of a draw, and the opponent accepts. In over-the-board play, the offer is made verbally: “I offer a draw.” If the opponent replies “I accept the draw,” the game ends immediately with each player scoring half a point. If the opponent replies “I decline the draw,” the game continues. In online play, the player presses the “Draw” button to make the offer.
Threefold Repetition: A threefold repetition of position occurs when the same pieces for the same player occupy the same level-positions on three separate occasions during the game, not necessarily on consecutive moves. When a threefold repetition occurs, the player whose turn it is may claim a draw. In online play, the player presses the “Draw” button during his or her turn, and if threefold repetition does not apply, a draw offer is made to the opponent.
Fifty Move Rule: The fifty move rule occurs when fifty consecutive moves by each player occur with no capture and no pawn movement.
Seventy Five Move Rule: In recognition of the greater complexity of Raumschach, the fifty move rule is extended to seventy-five moves for endgames involving only Rooks, Bishops, or Knights against a lone King.
In over-the-board play, the touch-move rule applies: a player who deliberately touches a piece must move it if a legal move exists. In online play, a move is committed upon confirmation (clicking or pressing the confirm button after selecting a destination).
No single commercial manufacturer produces a Raumschach set to an established standard. The IRF therefore defines the following minimum requirements for equipment to be considered regulation-compliant in rated over-the-board play.
Aa1 is light, then Ba1 is dark, Ca1 is light, and so on. Light and dark colors must be clearly contrasting, and easy on the eyes for long games. On transparent boards, the light color may be itself transparent or nonexistent.In Raumschach: Einführung in die Spielpraxis (1919, § 2.1), Dr. Ferdinand Maack provided specifications.
A standard digital chess clock is used for game with a physical board. One clock is positioned atop each tournament table. It must be equidistant from each player, reachable by each player, and must be at least 10 cm from the physical Raumschach set and from the edge of the table. Players are responsible for pressing the clock after completing their move on whichever level the move terminates. The button is to be pressed gently without punching, lifting, or knocking it over. Arbiters set clocks before move one. Recommended time controls are given in the Tournament Regulations below.
Table: For a game with a physical set, the table is regulated to be 115–130 cm long, 75–90 cm wide, and 58–62 cm tall. It must support 50 lbs. without wobbling, and the tabletop must be flat. Table legs may not be folding or have wheels without wheel-locks. Each chair is on the opposite side of the table. The Raumschach set rests atop the table, centered between the players, and the set is securely fastened to prevent sliding during games. Atop this table, level E is c.112 cm above the ground. The table is not allowed to wobble. Also atop the table is one digital clock — centered between the players, but off to either side — and by each player there is one writing utensil and one score sheet upon which each player records moves in standard IRF notation. The only items permitted to rest atop the table are the Raumschach set, digital clock, two writing utensils and score sheets, and each player may have a capped bottle for drinking. Each capped drinking bottle must be at least 30 cm from the Raumschach set. There is a limit of one game per table, and two players per game. Only arbiters and players are allowed within 1 meter of each table. Corridors between tables must allow easy access to an arbiter or player.
Chair: The choice of chair prioritizes player comfort and minimizes disruptions. The ideal chair is suitable for extended play without causing noise when moved, such as during arrivals or breaks. Each chair should be rigid enough to support proper posture. Organizers may provide high-quality office-style chairs, but players may request alternatives or bring their own if approved by the chief arbiter. The chair may have an adjustable height, so long as its operation is quiet. The chair may not have wheels. Any chair movement must avoid audible scraping or banging. The chief arbiter decides on chair suitability. Each player is required to have 4 square meters of space, centered around his or her chair, to accommodate the table and movement. When seated, the abdomen of each player should be 5–10 cm from the edge of the table, and each player in normal seated posture should be able to inspect the top level. The top level should not be above the eyes of either player. If the top level is above the eyes, a footrest may be supplied to facilitate shifting posture slightly higher to inspect the top level. A player may stand briefly to view or move on the upper levels.
For physical events, IRF game score sheets are used, which are available here. Each player may opt to use his or her own mechanical pen or pencil, otherwise a pencil will be provided. Each player is responsible for recording the details of the event, and all moves, onto his or her IRF game score sheet.
Overhead lighting must minimize shadows inside each Raumschach set. Direct sources of light that create strong glare or reflection are prohibited.
The IRF adopts and formalizes the notation introduced by Maack, with minor extensions.
A cell is written as: [level][file][rank], e.g. Cc3. In the normal form of Raumschach, levels are written in upper-case: A B C D E. In variants, levels are written in lower-case Greek: α β γ δ ε.
The symbol for stalemate was added for completeness, even though Maack did not use it.
♔ — King
♕ — Queen
♖ — Rook
🨢 — Unicorn
♗ — Bishop
♘ — Knight
♙ — Pawn
.
Piece codes are figurines to faciliate play between players who speak different languages.
Every move begins with a piece code, even a Pawn.
Note that the figurine for the Unicorn (🨢 = U+1FA22) may not render properly outside of Raumschach.org without a supporting font. On Raumschach.org, the GNU Unifont Upper is embedded for this purpose; it may be freely downloaded and installed from unifoundry.com/unifont/, after which it will render in most text editors, email clients, and Signal Desktop. Signal mobile does not render it, displaying a box instead; however, the underlying code point is preserved intact through copy and paste. If a Signal chat is emailed to the IRF administrator in a dispute, it will be opened in Emacs, which renders U+1FA22 correctly via font fallback.
The complete combination of piece code and source cell coordinates (such as ♘Ab1–Ac3) are always used.
A full position diagram of Raumschach Normal Form consists of five 5×5 chessboard diagrams, labeled A (bottom) through E (top), arranged either as a vertical stack or as a 1×5 or 5×1 grid. The label must be visible for each level. On levels A, C, E, the central square is white, per a picture from 1910 of Dr. Maack and his variant SIII5 A (Spielregeln zum Raumschach, 1913). Digital implementations may allow interactive rotation and three-dimensional rendering.
Adjournment is not allowed. Historically, a player was able to pause a long game due to fatigue, and to resume the next day. The time increments of modern clocks prevent such fatigue, and analysis with engines is forbidden.
Each year on December 1st–7th, the IRF hosts a world championship for Division 1A and Division 1B, held simultaneously. Registration for the event occurs in November 1st–15th. Selection via invitation begins on November 15th. An invitation is sent automatically to the former world champion to return to defend his or her (or its) title, and another invitation is sent to the next member of the respective division to be a challenger; the member with the highest IRF rating is always selected. Each member who receives an invitation is given 24 hours to respond, before the member with the next highest IRF rating is invited.
Until there is sufficient interest and availability for a physical match play, this is an online match play as live remote play. This match play is a classical tournament, and is a contest to be the first player to 6½ points within 12 match play games. A blitz game is used as a tie-breaker. In the first game, the challenger is White, and the color of each player alternates with each game regardless of outcome. There are two games per day, one in the morning, and one in the afternoon.
A reference time zone, called “tournament time,” is determined before each world championship. For a physical event, tournament time is the time zone of the event. For an online event as live remote play, tournament time is UTC (Coordinated Universal Time), which is GMT+0, the global standard. Online games begin at 15:00 UTC for round 1 of the day, and at 22:00 UTC for round 2 of the day. Physical games begin at 08:00 and 15:00 in the local time zone of the event, for round 1 and round 2 of the day, respectively.
Given the informal character of the IRF and the current rarity of over-the-board play, any Rated Member of at least six months’ standing may serve as arbiter for a tournament in which one is not competing. In the case of multiple arbiters, a chief arbiter is declared before the tournament.
Online tournaments are self-arbitrated by the platform, with disputes escalated to the IRF administrator.
Arbiters must be capable of communicating in English and Spanish, and communication may be assisted by technology.
To ensure the well-being of the players, there is a temporal break of at least 20 minutes between each successive game or round of games. During each break, each player may eat, drink, go to the restroom, and perform analysis (without the aid of electronic devices). Longer breaks are common for lunch or dinner, oftentimes one hour.
Players are expected to conduct themselves with courtesy. Analysis during a game in progress, the use of computer assistance in rated play, consultation with third parties, and unsportsmanlike behavior or harassment are all prohibited. Violation results in forfeiture.
Division 1A and Division 1B each hold a maximum of ten players. Division 2A and Division 2B are open pools. The following rules govern movement between divisions. All references to “season” mean the calendar year.
At the close of each season, the two players in Division 1A with the lowest cumulative game points across all four quarterly round robins are relegated to Division 2A for the following season. The same rule applies to Division 1B and Division 2B separately. A player who is absent from two or more quarterly events in a season without advance notice to the administrator is considered to have scored zero for each absent round and is subject to normal relegation rules.
If a Division 1 player voluntarily withdraws from Division 1 at any point before October 1st of the current season, the vacancy is filled by the highest-rated Division 2 player immediately. If withdrawal occurs after October 1st, the vacancy is filled at the start of the following season.
The two players in Division 2A with the highest cumulative game points across the three annual Open Swiss Qualifiers (March, June, September) are promoted to Division 1A for the following season. The same rule applies to Division 2B independently.
If two or more players tie for the second promotion spot, the tiebreak is: (1) head-to-head result across the season’s Swiss events; (2) the higher IRF rating at the close of the season.
A player who earned promotion may decline it and remain in Division 2 for the following season. The promotion slot then passes to the next eligible player by the tiebreak rules above.
In any given season, exactly two players are promoted from Division 2 to Division 1, and exactly two players are relegated from Division 1 to Division 2, preserving the ten-player cap. If Division 1 has a vacancy for any reason other than normal relegation, the administrator fills it by inviting the highest-rated Division 2 player at that time.
A newly registered member always begins in Division 2, regardless of rating, until they have completed a full season of Division 2 play and earned promotion through the normal route. This rule ensures that all Division 1 players have demonstrated performance under IRF tournament conditions and not merely a high provisional rating.
Forfeiture can occur for many reasons, including but not limited to conduct, a second illegal move in over-the-board play, absence from an online game for 10 minutes in classical play or 2 minutes in rapid play, being late 5 minutes to an event, using artificial backgrounds or obscuring the view in live remote play, and attending to other messages or phone calls in over-the-board play or live remote play.
When forfeiture occurs, the result is scored as a loss for the forfeiting player and a win for the valid opponent, with IRF ratings adjusted accordingly. Note that a double-forfeiture occurs when there is no valid opponent.
Any forfeiture may also result in suspension from future games in the same tournament and even future tournaments at the discretion of the arbiter. In online games, which may not have a designated arbiter, the IRF administrator fulfills the role of arbiter for forfeiture decisions.
The IRF recognizes four tournament formats for rated play. The appropriate format for a given event depends on the number of participants and the time available.
In a round robin tournament, every participant plays every other participant exactly once. With n players, the event consists of n − 1 rounds, and each player plays n − 1 games in total. A player who wins a game scores 1 point; a draw scores ½ point; a loss scores 0 points. The player with the highest total at the conclusion of all rounds is the winner.
Example. A round robin with 10 players consists of 9 rounds. Each player plays 9 games. The maximum possible score is 9 points.
The round robin is the most rigorous of the standard formats, because every player meets every other player directly. There is no luck of pairing; a player cannot benefit by avoiding a strong opponent. For this reason, the round robin is the IRF’s preferred format for Division 1 quarterly events and for the world championship qualifying pool.
A double round robin has each pair of players meet twice, once with each color. With n players this produces 2(n − 1) rounds and games. The double round robin further reduces the influence of the color assignment on outcomes and is appropriate when a deeper result is desired and time permits.
Scheduling. In a round robin with an even number of players, all games in a round may be played simultaneously, with each player having exactly one opponent per round. With an odd number of players, one player receives a bye each round (a half-point awarded without a game). The standard algorithm for constructing a balanced round robin schedule is the circle method: fix one player, rotate the remaining players around them one position per round. The administrator publishes the full pairing table before the event begins.
Color assignment. Colors are assigned so that each player receives White as close to an equal number of times as possible across the event. With an odd number of rounds, one color will necessarily be held one time more than the other for each player. The administrator determines color assignments before the event and publishes them with the pairing table.
Tiebreaks. If two or more players finish on equal game points, the tiebreak order is: (1) head-to-head result between the tied players; (2) Sonneborn–Berger score (the sum of the final scores of all opponents a player defeated, plus half the final scores of all opponents with whom a player drew); (3) a rapid playoff among the tied players.
The Sonneborn–Berger score rewards defeating and drawing against strong opponents. A player who beats a highly-scored opponent earns more Sonneborn–Berger credit than one who beats a weakly-scored opponent with the same game-point result. It is the standard tiebreak for round robins in preference to direct counting methods.
Time Control. Classical, with Rapid as a tie-breaker.
The Swiss System is designed for events with too many players for a full round robin, or where the time available permits only a limited number of rounds. No player is eliminated; all players compete in every round.
Pairing principle. Before each round, players are sorted by their current score in the event. Players are then paired against opponents with the same or similar score. In round 1, players are typically paired by rating: the highest-rated player meets the second-highest, the third meets the fourth, and so on. After round 1, players with 1 point play players with 1 point; players with ½ point play players with ½ point; and so on. As the event progresses, the pairings at the top of the standings become increasingly competitive, because only players who have won all their games remain on the maximum score.
This structure means that a strong player who wins every game will face progressively stronger opposition with each round, arriving at a reliable result without the event needing to schedule every possible pairing.
Number of rounds. The minimum number of rounds required to produce a reliable winner in a Swiss event of n players is approximately log2(n).
Scoring. The same point system applies as in round robins: 1 for a win, ½ for a draw, 0 for a loss. A player who receives a bye (awarded when the field has an odd number of players) receives ½ point for that round. No player may receive more than one bye in the same event.
Color assignment. The pairing algorithm tracks each player’s color history and attempts to alternate colors from round to round. No player should receive the same color more than twice consecutively. If a perfect alternation is not possible within a round due to pairing constraints, the player who is owed a color receives preference.
No rematches. Two players may not be paired against each other more than once within the same Swiss event.
Tiebreaks. If two or more players finish on equal game points, the tiebreak order is: (1) Buchholz score (the sum of the final scores of all opponents a player faced); (2) Buchholz Cut-1 (the Buchholz score minus the score of the lowest-scoring opponent); (3) the higher IRF rating at the start of the event.
The Buchholz score is the Swiss equivalent of Sonneborn–Berger: it rewards players who faced a stronger field. A player whose opponents all finished well has a higher Buchholz than a player with the same game-point score whose opponents performed poorly.
Open and closed Swiss events. An open Swiss event accepts any eligible player without prior qualification; registration is the only requirement. A closed or invitational Swiss event restricts entry to selected players. The IRF’s Division 2 Swiss Qualifiers are open events.
Time Control. Rapid/Classical mix. All games use the rapid time control, except for the final round, which uses the classical time control.
A bilateral match between exactly two players. The match consists of at least 4 games, with colors alternating each game regardless of result. The player who wins the most games wins the match; draws are counted as ½ point for each player. The IRF ratings of the two players must be within 400 points of each other for a match to be rated.
The world championship is a specific form of match play: a contest to reach 6½ points within 12 games, with a blitz playoff if the score is tied at 6–6 after all classical games. The full provisions of the world championship match are given in the Annual IRF World Championship section above.
A thematic tournament may take any of the above formats (round robin, Swiss, or match play). All games begin from a prescribed opening position agreed and announced before the event. Thematic tournaments are suited to theoretical investigation of a specific opening or middlegame structure. They are fully rated provided all other tournament regulations are observed.
Both players must be either human or inhuman (LLM). Human vs. inhuman is forbidden. Human and inhuman players are in separate divisions. In any case, external assistance is forbidden.
In over-the-board play, the first illegal move results in a warning and correction; the second illegal move results in forfeiture of the game. In online play, the software interface prevents illegal moves.
The tournament schedule depends on the number of players, and is subdivided into three phases.
The following provisions govern the IRF’s tournament calendar during its founding period, defined as any calendar year in which the total number of Rated Members is fewer than twenty. These provisions supersede the mature annual calendar for the duration of the founding period. When the total number of Rated Members reaches twenty at any point during a calendar year, the mature annual calendar takes effect at the start of the following calendar year.
When there are 2-19 rated members, there are 3 open Swiss Qualifiers (March, June, Sept.) and a world championship match in December. There are divisions A and B, but not 1 and 2. All human players compete in a single pool, and the invitation is open. No promotion or relegation rules apply.
Outside of this annual event, players are encouraged to arrange match games and correspondence games at any time. All such games are rated.
The IRF administrator announces the transition from the founding period to the mature annual calendar no later than October 1st of the year in which rated membership reaches twenty, so that Division 1 invitations may be issued in time for the following year’s Q1 event.
| Month | Division | Event |
|---|---|---|
| Jan. | 1A,1B | Q1 Round Robin (Classical, 9 rounds) |
| Mar. | 2A,2B | Swiss Qualifier (Rapid/Classical mix) |
| Apr. | 1A,1B | Q2 Round Robin (Classical, 9 rounds) |
| June | 2A,2B | Swiss Qualifier (Rapid/Classical mix) |
| July | 1A,1B | Q3 Round Robin (Classical, 9 rounds) |
| Sept. | 2A,2B | Swiss Qualifier (Rapid/Classical mix) |
| Oct. | 1A,1B | Q4 Round Robin (Classical, 9 rounds) |
| Dec. | 1A,1B | World Championship Match |
Each spectator must stay at least two meters from any physical Raumschach set, often behind a rope barrier. Spectators cannot walk between boards, stand opposite players, or interfere with games; they may only alert arbiters to irregularities. When a player finishes a game, that player becomes a spectator and must follow the same rules as any spectator.
For any spectator to be allowed in the same room as the physical Raumschach sets, the spectator is forbidden from bringing mobile phones, electronic devices, or flash photography — with the exception that flash photography is allowed in the first five minutes of a game.
Non-smart, non-electronic sunglasses are usually permitted. Anything resembling smart glasses or wearable electronics can be banned on anti-cheating grounds. If there is a medical need (light sensitivity, eye surgery, etc.), arbiters are typically accommodating, especially if informed in advance.
If you plan to wear sunglasses during an event, email the chief arbiter beforehand and get explicit approval in writing.
| Format | Time Control | Notes |
|---|---|---|
| Classical | 90 minutes + 30 seconds/move increment | Standard for rated over-the-board and correspondence-equivalent online play. |
| Rapid | 25 minutes + 10 seconds/move | For rapid tournaments and club evenings. |
| Blitz | 5 minutes + 3 seconds/move | Informal only; blitz games are unrated. |
| Correspondence | 3 days per move | For asynchronous online tournament play; see § VIII. |
Wearable electronics are forbidden to be worn by players while playing a game in a tournament because of the potential for cheating. Examples include digital watches, earbuds, fitness bands, headphones, smart clothing with built-in sensors, smart glasses, smart rings and other smart jewelry, smart watches.
Given the practical difficulty of assembling players around a physical Raumschach apparatus — which requires construction or purchase of a multi-level board — the majority of IRF play is expected to occur online. The federation therefore treats online play as fully equivalent to over-the-board play for rating and tournament purposes, provided that the official rules are in effect. There are two forms of online play: live remote play and correspondence play.
The IRF-recognized implementation of Raumschach is available at:
This implementation enforces the official piece movements, starting position, and promotion rules as described in § IV of this document. It provides an interactive three-dimensional board rendering. Rated members wishing to submit game scores for rating purposes should export the Raumschach Game Notation (RGN) from their games, and submit the .rgn files via the Game Results contact form.
Live Remote Play is synchronous play conducted via a video communication platform (such as Signal) where both players are mutually visible and audible for the duration of the game, simulating the conditions of over-the-board tournament play.
Players in a cross-language pairing should agree on a working language before the game begins; in the absence of agreement, English is the default language of all non-notation communication.
At the agreed time, each player enters a private room, alone, having a chair and table, mobile device with a camera (typically a smartphone), and a tablet. The cover of the tablet is folded, so the tablet is not flat on the table, but angled for mutual viewing. There is an imaginary equilateral triangle on the table between the player, tablet, and mobile device. The camera on the mobile device is set so it can see the player and tablet at all times.
The White player uses Signal to video-call the Black player; once connected, each player can see the other player and tablet — and thus the other’s game — throughout the game. This is very similar to a traditional in-person tournament. If the White player does not call within five minutes on or after the agreed time, or the Black player does not answer when called, the game is forfeited to the other player.
Players must enable their smartphone cameras via Signal to simulate an in-person experience. This allows opponents to verify authenticity and maintain fair play. The camera must clearly show the full face and upper body at all times, with no masks, filters, hats, or obstructions hiding identity. The real physical background and playing area must remain fully visible and unaltered — no virtual backgrounds, blurring, image overlays, or other digital effects for privacy or any reason are allowed. Lighting should ensure the person and surroundings appear genuine and undistorted, preventing any suspicion of pre-recorded footage or deception. Violations, such as obscuring the view or using artificial backgrounds, results in game forfeiture.
Beginning with the White player, each player slowly turns around his or her mobile device, the camera, showing that there are no external devices, other people, or other sources of information that can affect the game; the full face and upper body of the player is not required to be visible during this demonstration. Each player is responsible for the sanctity of his or her immediate environment. Each room should be satisfactorily quiet to both players.
Each mobile device must be set to vibrate only, to minimize interruptions. Each player may not attend to other messages or phone calls during a game, without forfeiting the game.
Next, each player demonstrates to the other player that the Raumschach web game is running in Firefox on his or her tablet, both visually and aurally. Each player opens the Firefox browser, and opens the webpage for the web game. Next, each player holds the tablet close to the mobile device so the other player can verify the URL is correct. Lastly, each player demonstrates that the sound of the clock in the Raumschach web game is audible to the other player, by beginning a web game and beginning the clock (which makes a sound), and confirming the other player can hear it. Then, each player presses “New Game” to reset the game, then pauses their clock.
With the player, tablet, and mobile device in their affixed positions, each player verifies that the other player can see that the Raumschach web game is open on the tablet of the other player; no other apps should be running on the screen. Each player does not need to see perfectly the details of the game of the other player, but must verify that is what is running.
The White player customarily texts the figurines (♔ ♕ ♖ ♗ ♘ 🨢︎ ♙) to the Black player, so that the figurines are easily available in either chat history.
The White player unpauses his or her clock (it beeps), and the game begins.
During the game, the White player makes a move in his or her web game, at which time his clock stops. Since his opponent is remote, he or she must pause the Black player’s clock, which started automatically when White moved. The White player observes the latest move in his or her move list, and texts this move in Signal to the Black player. The Black player then makes the appropriate move for the White player in his or her web game, which begins his or her clock. While moves are communicated, no clock is ticking.
The work-flow is:
Texting is preferred to speech, because of mishearing or misunderstanding, and this gives you a timestamped, text-record audit trail automatically, eliminates mishearing, and the chat log becomes the primary dispute document.
After the game, results are communicated in English or Spanish via email to the IRF administrator by both parties. When there is no dispute and results are identical, the results are posted on the website. When there is no dispute and results differ, both players are notified. When there is a dispute, the IRF administrator requests the Signal chats of both players. Players may use Signal Desktop to access a chat and copy/paste it into a text editor. Once received, the dispute will be analyzed and the verdict can be communicated back to the players, and the results noted on the website.
In a tournament with live remote play, each player must confirm readiness to the administrator no later than 60 minutes before the scheduled start of each round; failure to confirm is treated as forfeiture of that round. Both players must submit results within 30 minutes after game completion. If no result has been received within 7 hours (Classical), 3 hours (Rapid), or 45 minutes (Blitz) after the scheduled round start time, the IRF administrator may inquire via Signal; if there is no response within 30 minutes, a double forfeit is declared.
Correspondence games are conducted by e-mail or through any agreed asynchronous medium (such as Signal), using IRF Standard Notation. The default time limit is three calendar days per move, beginning at the moment the previous move is transmitted. Players should acknowledge receipt of their opponent’s move. Time used for national holidays (up to seven days per year, declared in advance) may be exempted by mutual agreement.
Players using the web game at raumschach.org/raumschach.html should select the Friendly game type (no time-control). The correspondence time limit of three calendar days per move is governed by the date and time of each move’s transmission, not by the web game’s internal clock.
In correspondence games, players are explicitly permitted to consult chess engines, analysis tools, books, databases, and any other external sources of information. This is a traditional feature of correspondence play and is fully sanctioned by the IRF. The use of such tools as analytical aids does not affect a human player’s classification as a human member under the rating system.
Since the web game does not persist state between sessions, players are advised to keep a copy of their move list at all times. This is good practice in any case, as the move list forms the game score required for submission. To recover a game after closing the browser or rebooting, open a new Friendly game and replay each move in sequence from your saved list.
Correspondence games between any two Rated Members may be arranged at any time by mutual agreement, without reference to the tournament calendar. Such games are fully rated under the EloR system provided they are played at the correspondence time control (3 days per move), conducted in IRF Standard Notation, and submitted to the administrator within thirty days of completion. Correspondence games count toward all rating thresholds and title qualifications in the same manner as tournament games. There is no annual limit on the number of correspondence games a player may submit.
Players wishing to find correspondence opponents are encouraged to visit the Results Register and browse the Active Rated Players for players who have indicated an interest in playing correspondence games. Members with Signal usernames can contact each other.
All rated games must be submitted as a complete game score in IRF Standard Notation, accompanied by the players’ names, date, time control, and result. Incomplete scores will be accepted only when the decisive position can be reconstructed and verified.
The IRF uses a modified Elo system, dubbed EloR, which is adapted to the expected characteristics of Raumschach play: longer games, greater drawing probability in some endings, and a smaller player pool than ordinary chess. The K-factor schedule is as follows:
| Category | K-factor | Condition |
|---|---|---|
| New Member | 40 | Fewer than 30 rated games. |
| Established | 20 | 30 or more rated games, rating below 2,200. |
| Senior | 10 | 30 or more rated games, rating 2,200 or above. |
New players begin with a rating of 1,500. The initial pool of rated players will calibrate against one another; absolute values of ratings should be interpreted with humility until the pool is sufficiently large.
The EloR system is applicable between human players, and between inhuman players (LLMs), but is forbidden between a human player and an inhuman player.
In the spirit of play rather than prestige, the IRF offers the following informal titles, conferred by the administrator on the basis of the published rating list:
The IRF regards the dissemination of theoretical and practical literature as central to its mission. Raumschach cannot grow without material for players to study.
The most substantial theoretical work on Raumschach currently in existence is a six-volume series, The Complete Raumschach Theoretical Series (Claude, 2026), authored by Claude Sonnet 4.6 under the direction and editing of a human researcher, Avidius Du Vide. This work is available at the following addresses:
These volumes represent, to the knowledge of the IRF, the most rigorous analytical treatment of the game since Maack’s own 1907–1909 contributions to Deutsches Wochenschach. Members are encouraged to read, annotate, and respond to them.
The playable implementation at www.raumschach.org/raumschach.html allows any visitor to learn and practice the game without any installation or account. It is offered freely and without restriction.
Ferdinand Maack’s Anleitung zum Raumschach: Dreidimensionales Schachspiel (Hamburg, 1908) is in the public domain and has been digitized. This text has been translated into English and Spanish, and these translations are available on the raumschach.org site. All members are urged to read it: it is short, brilliant, and surprisingly modern in its thinking.
When membership and contributed material are sufficient to warrant it, the IRF intends to publish an irregular bulletin containing: annotated games, problems and studies, theoretical articles, news of tournaments, and historical research. Contributions are welcomed from any member at any time.
Raumschach theory is, in Maack’s own words, “still awaiting development.” The opening theory of even the most common lines is almost entirely unexplored. Endgame tablebases do not exist. The relative value of pieces in standard positions has never been empirically established. The aesthetic vocabulary of three-dimensional chess problems has barely been sketched. In every direction, the field is open.
The IRF encourages the following research activities and will publish contributions addressing them:
The IRF is constituted as a de facto voluntary association without legal incorporation. It has no officers in the corporate sense, no bank account, and no physical headquarters. Its authority derives solely from the consent of its members and the coherence of its published standards.
The charter exists in two languages: English and Spanish. In case of a discrepancy between the English and Spanish texts, the English text governs.
The federation is presently administered by its founding custodian, Avidius Du Vide, who maintains the website, processes game score submissions, publishes the rating list, and communicates with members. The custodian reserves the right to appoint one or more co-administrators as activity warrants. The administrator’s powers include membership revocation as described in § III.
The Official Tournament Rules (§ IV) may be amended only after a consultation period of not less than three months, during which any Rated Member or Contributor may submit a written argument for or against the proposed change. Amendments require the agreement of the administrator and a majority of responding members. Rule changes do not retroactively affect past ratings.
Should the IRF ever become inactive, all published materials shall remain freely available in perpetuity. The federation’s records, game scores, and publications shall be submitted to an appropriate public archive.
All correspondence — membership registration, game score submissions, problem contributions, questions, and general communications — should be directed to contact the IRF administrator: Avidius Du Vide.
We are a small gathering, and likely to remain so. We consider this a distinction rather than a deficiency. The game is its own reward. New members are welcomed with genuine pleasure.
Given under the seal of the IRF,
founded in cyberspace in the year 2026.