2026

Royal Reversi

Royal Reversi is an Othello variant for two to six players and played on a modified board.

The game was introduced in the book Reversi and Go Bang (1890) by an author mysteriously named 'Berkeley' [archive.org]. Here are the relevant pages:

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A later iteration of this game was commercialized in 1938 as Chameleon at Milton Bradley.

The official rules:

Here's the review of Chameleon from The Gamer #7,

Pasta

Pasta is a 1956 game by Alvin Paster, published in Computing News magazine, issue #73.

The game is a stacking Checkers, from the family of Bashni and Laska.

The original source seems to be lost, but I found an article about the game from the 1970s magazine Popular Computing #12, edited by Fred Gruenberger,

The game is also mentioned by David Parlett's The Oxford History of Board Games (pg.139) and Stephen Addison's 100 Other Games to Play in a Chessboard (pg.57).

The evolution of stack-based Checkers starts at 1875's Bashni, going next to 1911's Laska (a variant of Bashni) and usually the next mentioned game is 1960s' Stapeldammen (going then into modern times with games like Emergo). Pasta is a link we can place between Laska and Stapeldammen, despite being not that original.

Thrall

Thrall is a 2005 game by L. Lynn Smith, published online.

The game is played on the following hexagonal tiling:

Each player has one piece, and there are enough wall pieces on reserve.

Rules:

• Initially, players drop their respective pieces on an empty hexagon
• On his turn, first the player slides his piece over a line of empty hexes, then places a wall piece on an empty triangle
• pieces cannot move between two occupied adjacent triangles
• Wins the player that stalemates the adversary
  

In the following position, White is winning because he enclosed the black piece is a smaller area, comparing with the area his piece is confined.

There is a ZRF to play Thrall.

Dioxoid

Dioxoid is a 1982 game by Ken Totten, published at Tau-10 Games.

The game is supposed to represent an oxygen molecule (O₂) where the large circles are the nuclei of the two oxygen atoms.

The rules:

• Setup: each player places his eight pieces (called electrons) in the marked double circles.
• On his turn, the player moves a friendly electron to an empty circle.
• If an electron moves or bounces to a circle adjacent to two other electrons, those must bounce away from the first (moving to adjacent empty circles in the opposite direction).
• If an electron moves or bounces to a circle adjacent to another electron that cannot bounce (e.g., is at the edge or near a nucleus), then it is the first electron that must bounce away in the opposite direction.
• These bounces might produce a chain reaction, bouncing more and more electrons until all stabilize.
• Ko rule: a move cannot repeat the position of the moving player's previous turn.
  
• The player that first move his electrons to the adversary's double circles wins the game.
• However, if the other player can finish in the next turn, while also being the player that started second, then the game is a draw.
  

note: the rules are not specific to where the bounced electrons should go to. But considering the chemical metaphor, and the rules stating that a piece at the edge cannot be bounced, I assume the bounce must be in the opposite direction of the moving electron.

NoGo

NoGo is a 2005 game by John Moore.

This is a game using the concepts and rules of Go, with some simplifications.

Rules:

• On her turn, the player drops a friendly piece on an empty intersection such that all existing groups of pieces (of either color) have, at least, one liberty (so, no captures or suicides are allowed)
• Wins the last player to move

Black moved last; there is no valid drop left,
so Black wins the match

This is a game that can be analyzed by the tools of Combinatorial Game Theory. The game can be split in a sum of games, when parts of the board no longer interact. For example, using a one-dimensional NoGo, the game o..xxo..xx can be split and simplified by two (in this case equal) subgames: o..x and o..x; this type of property is crucial to computing large game positions.

Moore initially called the game Anti-Atari Go at Sensei's Library. The name No Go meant, back then, another different go variant: After a player has made a move, his opponent may refuse it, and he must make another one. The opponent may not object to this second move (this variant is now known as Forced Takeback Go at Sensei's Library).

There's a ZRF and a Ludii to play the game.

Megiddo

Megiddo is 1985 game by Steve Baldwin, associated with several different publishers.

The board is made of six concentric rings under a central six-point start. There are 36 pieces of three different colors (the third color is for the three-player version):

• Each player, on her turn, drops a friendly piece on an empty circle.
• Captures are custodian: if a piece is dropped, and there are two enemy pieces and then a friendly piece, all in the same direction, then the two enemy pieces are captured, and replaced by two friendly pieces.
• The allowed directions are (a) in the same circle, (b) in the same line, (c) making a spiral on concentric circles (cf. next example)

• Captures can occur in multiple directions at the same time
• Also, captures create a chain reaction: the new pieces that replace the captured ones might produce new captures, and so on. But notice that first all multiple captures must be executed before considering chain reactions.
  
• Pieces are always captured in pairs.
  
• Wins the player that either (a) captures six enemy stones, or (b) makes one of the three winning six-piece patterns, named radial, circular, and spiral:

The rules propose a multi-match game until one player reaches 36 points:

• Winning with a winning pattern: 6 points
• Any extra winning pattern: 12 points
• Each captured piece: 1 point
  

The rules also mention a 'Cleopatra' variation: the typical custodian capture does not apply if a player drops a piece between two enemy pieces, rule which the game follows. In Cleopatra, dropping a piece inside will capture the pieces on the extremes:

Here are some tips from the original rules:

The game is a variant of Pente (which itself is an iteration of Gomoku-ninuki). The fact that there are three very different types of direction (radial, circular and spiral) removes clarity to the game. Unless players are attentive, they will miss captures and even winning patterns.

Unlike Pente, it is easy to start using pieces at the edge, which have the advantage of being harder to capture. I'm not sure if this is good or bad, but it is an important feature in this game. The tips mention 'taboo points', places where a player has a winning threat if the adversary plays there, which is something common in the moku family. Matches will converge into a cold phase, where the first player forced to play in one of those points, immediately loses the game.

A review on GAMES #67:

Intermezzo

Intermezzo is a 1993 game by Reiner Knizia, published in Spielbox magazine.

The game is played on 9x9 or 9x10 board initially empty. Each player has 33 pieces.

Rules:

• On her turn, the player either:
• drops a friendly piece on an empty square
• calls an intermezzo on a friendly piece: then all horizontal and vertical lines of empty squares between that piece and other friendly pieces, are occupied with new friendly pieces
• Wins the player that places all her stones on board

This position was shown in the original article:

after 12 moves, Black makes the first intermezzo on piece [1]

This is a pencil & paper game, no need for physical pieces to enjoy some matches.

The Spielbox article (in German):

The Game of Passo

The Game of Passo is a 1919 game by Leonard Budd Gaylor, which was self-published.

The game is played on a Checkers board, so only the pieces were sold,

Each player has ten pieces and one ball. The pieces are concave on top and can hold the ball.

This is the initial setup:

The balls are placed at e1 and d8.

• The player, on his turn, either (a) moves one friendly piece, or (b) passes his ball to another friendly piece in moving range (assuming it didn't have the ball).
• A piece without the ball can move like the Chess Queen.
• A piece with the ball can move one step diagonally (forwards or backwards) .
• There are no captures.
  
• Wins the player that either moves his ball to his last row, or surrounds the enemy ball such that it cannot be passed.
• If a player blockades all access to his first row, on his half of the board, he loses the game.

I find it interesting that the rules acknowledge an obvious drawish strategy of blocking all ways to pass through. They still leave that possibility in the opponent's area, which seems fair, since it is quite difficult to achieve that. The rules feel quite modern, despite the game is now a century old.

A rule page from that time:

The game was patented as US1363769 in 1920. Here's the visual description of the two types of pieces:

More about the game and the author in AGPI Quarterly volume 8 [1].

Steppe

Steppe, aka Stak, is a 1985 game by David Rea, published in DMR Games and Tactical Studies Rules.

Steppe is a tiling game played on a 5x5 board. Each player has fifteen 1x1 tiles, five 1x2 tiles and three 1x3 tiles (the colors are Blue and White). There's also six 1x1 red tiles, where each player gets three.

In the TSR edition, the white tiles are the neutral ones

Each match consists of three phases, each ending when the board is full:

• On the first phase, players take turns dropping one of their available tiles over empty board squares.
• Each 1x1 tile values one point, each 1x2 values five points, each 1x3 values ten points. 
• Red tiles are not scored, i.e., they are worth zero points.
  
• The second and third phases are the same, but the points are multiplied by 2 and 3, respectively.
• For each phase, the player that places the last tile starts the next phase.
• In any phase, if one player cannot place more tiles, then the other player will continue playing until the board is full or he is unable to continue.
  
• There are also requirements for placing tiles:
• Red tiles are owned by both players, assume the board is made of 25 red tiles; there are no restrictions in placing red tiles, or placing other tiles on top of them.
  
• 1x1 and 1x2 tiles must be placed on top of tiles owned by the current player.
• 1x3 tiles can only be placed if their extremes are on top of tiles owned by the current player; the middle section can be over any color but it cannot be over an empty square.
  
• When the third phase ends, the player with more points wins the game.

The official rules include some strategy tips:

• The first level is your basic foundation. You want to place your tiles into patterns that will allow you to place large tiles on top of them in the upper levels. If you want to place a "five" in a certain location in the second level, you'll need to have two tiles of yours together in the first level. You must think ahead to what you want in the third level, so you need to try to set up the second level by setting up the first level.
• Not only that, but a big part of setting up the second level usually means going first in the second level. Which means placing the last tile in the first level. Which means a move/counter-move situation:
• White goes first and there are 24 spaces to be filled in the first level. So if each player places "ones" on every turn, blue will place the last tile in the first level, and thus go first in the second level.
• If white wants to go first in the second level, he'll have to place a "five" (which takes up two spaces) in the first level. If both players then place "ones" on each turn in the first level, white will place the last tile in the first level. But, if blue places a "five" ....
• Once you get to the second level, you'll want to not only try to complete your planned pattern (so you can place the tiles you want in the third level), but you'll probably want to disrupt your opponent's pattern. That's where red tiles come in. If your opponent has set up a string of three tiles of his color in the first level (so he can place a" ten" on top of them in the second level) you can place a red tile on top of the middle tile (when you're in the second level) to block.

a complete match of Steppe, White wins 151-115

 

The game was mentioned in GAMES #87:

Games with Othello pieces: Blocs and Troll

These are two games found in Jeux et Stratégie #43, printed in February 1987.

The first game is called Blocs. It is played on a 4x4 board with 16 Othello pieces.

• Initially, players take turns dropping one piece on an empty square, with its face turned up, until the board is full
• Then, on his turn, the player must select a rectangle of pieces (it can be as small as an isolated piece, or as large as the entire board) that has a black piece on its lower-right corner. Then the player flips all the rectangle's pieces.
• It is assumed that both players are facing the board from the same side. If they are opposite to each other, then the other player can only flip rectangles with a black piece in its upper-left corner.
  
• Wins the player that moves last (i.e., the first to make the board all covered with white pieces)

Here's the J&S text:

At first the game seems to allow endless matches, since we are flipping pieces on and on. But that is not so. The lower-right most pieces, after becoming White, will never be flipped again. So, each board constructed at the initial phase has a budget that is spent on every turn, making the game end sooner or later.

The text mentions John Conway as the game author. I was unable to find the English name of this game. In the book Winning Ways, chapter 14 is dedicated to Turning games, but this specific ruleset is not included. 

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The second game is Troll by Jean-Claude Rosa. It is played on an 8x8 board with 64 Othello pieces (i.e., the entire Othello set). 

The rules are like Othello except:

• One player owns the left and right edges of the board, while the other owns the top and bottom edges
• Capturing/flipping enemy pieces is only mandatory in the squares owned by the adversary (his edges, including corners). So, a piece can be dropped on an empty square, in the middle of the board, without making any capture.
  
• Wins the player that makes a connection between his edges (diagonal connections are not valid)
  

This game is indexed at BGG.

Duell

Duell, aka Conquest, is a 1975 game by Geoffrey Hayes, published by Alga (among others).

The game is played on an 8x9 board. It uses dice, not as random generators, but as pieces. Each army has eight regular dice, plus a 'key piece' with one dotted star on every side.

The setup is as follows (with all faces 4 facing inwards):

The rules:

• Regular dice move by 'tumbling' their faces over the next empty square (there's no diagonal moves; there's no jump over other pieces).
• The initial move must be forward or backward
• Pieces can also turn right or left during the move; this can be done just once during the move
  
• The number of moves is given by the die's top face; the piece cannot stop until the entire move sequence is done
• Key pieces can only move one square per turn (after all, all their faces have a one)
• Capture is by replacement and is only possible at the last square of the moving piece
  
• Wins the player that captures the enemy key piece; or moves his own key piece to the initial square of the enemy key piece (so White's moving from e1 to e8, or Black's from e8 to e1).
  

move examples from the rule book

Some hints given by the rule book:

• It is sometimes possible to approach one square from two different paths.
• Your choice of path will determine what number will be on the "top face" of your piece at the conclusion of the move.
• Your strategy can include planning for a subsequent move if you can control the top number and space location.

Here's a review from GAMES magazine #2: 

And from Games & Puzzles #48:

There are not that many abstract games using dice as pieces. We already mentioned Chase (1985) here in the blog. Other examples are Mojave (2004) and Cublino (2006).

Tris

Tris is a 2006 game by Daniel Solis.

The game is played on an 8x8 board, initially empty. Each player has enough pieces of one color (probably 40 is more than enough).

Rules:

• On his turn, the player either:
• drops a friendly piece, on an empty square, at the first/last row or vertically connected to another piece (or either color)

 all legal next drops shown

• moves a piece to a horizontally adjacent empty square
• then, the piece 'falls' until meeting another piece (falls in the direction of the edge supporting its column of vertically connected pieces)
• if there were pieces on top of the moving piece, those pieces also 'fall' 

all movements available

• If, after the drop/move, an orthogonal or diagonal 4 in-a-row of pieces of the same color is made, those pieces are removed from the board (cf. next rule for exceptions)
• the remaining pieces fall accordingly, which might produce more 4 in-a-rows, and so on...
• Fixed pieces: the pieces at the first/last row are fixed and cannot be removed
• when a row is full, those pieces also become fixed
• A player wins if either:
• his first four rows are full
• twelve of his pieces are removed
  

Comment from the author: Pretty simple game here, essentially taking elements of Tetris and Connect 4 and laying it flat on a board instead of vertically.

Hexagonia

Hexagonia is one of the first two hexagonal Chess in the literature^(*), c.1860. It was published by Jaques & Son, and its author is possibly J. W. Smith [1].

A new game for two players, played on a board divided into hexagons. Each player had fourteen pieces, representing infantry, cavalry, and artillery, and one principal piece, the King. The various pieces have certain moves on the board analogous to those of a real army, and the game is won by the player who first succeeds in placing his King (without liability to capture) on the central hexagon.

In Cazaux and Knowlton's A World of Chess, [2], the game is described. Each army is composed of one King, two Cannons, four Knights and eight Pawns. However, it is not known how the pieces moved. The book also refers that this game appears to have been invented, some years earlier, in New Zealand.

The book also includes the following quote about the game (page 377):

The last game which we have to notice is undoubtedly the most scientific of the lot, and somewhat resembles chess. It is called" Hexagonia," and is published by Mr. Jaques, of Hatton Garden. The board is in the shape of a hexagon, and contains hexagonal figures, painted red, blue, or white. Two play at this game. To each combatant is given a king, four knights, and two pieces in the shape of cannon, called artillery, and eight pawns, or pieces of infantry. Each piece has a different mode of moving, and can capture an enemy; and the object is to place the king on a gold square in the centre of the board. This sovereign can never be taken, but can be checked as in chess. The reader will gather fom this that much head-work and tact can be brought into play in this game, and that a knowledge of chess is often highly advantageous. We have endeavoured somewhat briefly to state the chief points of the new in-door games. We feel sure that they are varied enough to please the tastes of everybody, and we sincerely hope that our youngfiends may enjoy many a pleasant hour in the enjoyment of the intricate manoeuvres that these games involve" (Edmund Routledge, "The New Winter In-door Games," Routledge's Every Boy's Annual, an Entertaining Miscellany of Original Literature, George Routledge and Sons, 1866, New York, p. 35)

Pritchard's book, [3], also refers to the game: 

Hexagonia (Proprietary game, John Jaques and Son). Published in 1860 according to van der Linde, and allegedly awarded two prize medals in 1862, the game was in fact published on 23 September 1864 and registered at Stationers’ Hall the following January. 127-cell hexagonal board, central cell distinguished. Each player has 1 x King, 2 x Cannon (artillery), 4 x Knight (cavalry), 8 x Pawn (infantry). The moves of the pieces are not recorded. The object was to get one’s K safely to the central cell.

About the piece's moves. The King, Knight and Pawn moves are directly translated to hexagonal boards. The Cannon however could have been like a Rook, sliding rows of hexes, or like Bishops sliding thru diagonals, which might explain the use of three colors in the Hexagonia board (since it makes it easier to follow these diagonals). Both hypotheses for the Cannon would be stronger than the Knight's, which is compatible with their smaller number (two) compared to the Knights' (four). However, this is just speculation.

Since the game's goal is not to capture or stalemate the enemy King, it's arguably not a chess variant, but most of Chess themes are here, nonetheless. The first known hexagonal Chess with checkmate was 1910's Mars by M. van Leeuwen and published by F. H. Ayres.
______

(*) the other early Hexagonal Chess (also without checkmate) was designed by Thomas Hanmer Croughton, c.1853.

[1] Michael Thompson, Hexagonia, https://michaelthomson.org/game/hexagonia
[2] Jean-Louis Cazaux, Rick Knowlton - A World of Chess (2017)
[3] David Pritchard's The Classified Encyclopedia of Chess Variants (2007)

The commercial offsprings of Chess: Ploy

Ploy, aka Imperium, is a 1970 game by Frank Thibault, published by 3M among other companies. 

The initial setup:

The rules by Mats Winther from his Zillions implementation:

The goal is to capture the enemy Commander, or reduce the opponent army to a single Commander. Each piece has an indicator which determines at which directions the piece can move. This can be altered by rotating the piece 45 degrees, left or right (a direction move). Rotating the piece costs a move.

Each player has three Shields, five Probes, six Lances, and one Commander. The Shield moves one step and has only one movement freedom at any time. The Probe slides two steps and has two freedoms. The Lance slides three steps and has three freedoms. The Commander has four, but can only move one step.

A player must either make a direction move or a motion move. The three Shields are the only pieces that can perform a direction move immediately after a motion move. Capture occurs by displacement

Winther also includes some tactical advice:

This game seldom ends in a draw. It is sometimes worthwhile to sacrifice material if you can gain an attack on the Commander. When the pieces become scarce, the Commander is more vulnerable to attack. As it can only move four ways, it cannot easily escape. The Lance with the three forward directions is especially suited to attacking the Commander. Remember that you can also win by capturing all enemy pieces except the Commander.

The game can also be played with Ludii.

The official rules:

Here is a review of the game at Games & Puzzles #22:

The game was seriously promoted as shown by this full-page ad in The General magazine #13:

There is a similar game, but played on a hexagonal board, Michael Flynn's Omnigon (1998):

More information about this game at chessvariants.com.