eykoss^{TM } playing field 
see also: eykoss^{TM } rules 
see also: eykoss^{TM } moves 
see also: eykoss^{TM } notation 
spheroidal surface 
The playing field is layed out on the surface of a spheroid that comprises a 3frequency icosahedron. 
An icosahedron is a geometric shape (one of the Platonic solids) with 20 triangular faces on its surface. 
triants 
On a 3frequency icosahedron, each of the triangular faces is subdivided into nine triangular spaces. Each of the 20 triangular faces is referred to as a triant (called a "triant" instead of a "quadrant" because each contains triangles instead of quadrangles). 
The 180 triangular spaces make up the playing field. Each of them has one of the four colors or patterns on it: one for each of four players. There are 45 spaces of each color or pattern. In the illustrations here, these four colors are used: mountain (brown), jungle (green), sea (blue), and sand (tan). There is a particular layout of the colored or patterned spaces on each triant, and this layout helps to identify each of the 20 triants. 
corner spaces, edge spaces, inner spaces 
There are three kinds of triangular spaces. On each triant, three of the spaces are referred to as corner spaces: each corner space is in one of the corners of the triant. And so the corner space touches two triant borders with two of the space's edges. Three of the spaces are referred to as edge spaces: each edge space is along one of the triant borders in the middle of that triant border. And so the edge space touches one triant border with one of the space's edges. Three of the spaces are referred to as inner spaces: each inner space does not touch any triant border with any of the space's edges. And so the inner space touches two triant borders but only with two of the space's vertices. 
edge rows, middle rows 
Each triant has three rows of spaces that are referred to as edge rows. Each edge row has five spaces: the five spaces that touch one triant border either with one of the space's edges or with one of the space's vertices. And so the row starts with a corner space, goes through the adjacent inner space, then the adjacent edge space, then the adjacent inner space, and ends with the adjacent corner space. Each triant has three rows of spaces that are referred to as middle rows. Each middle row has three spaces: the three spaces alongside one of the edge rows. And so the row starts with an edge space, goes through one of the adjacent inner spaces, and ends with the adjacent edge space. 
pawns, pieces 
Each of the four players begins with 16 men: the same men as in chess. Eight of them are pawns, and eight of them are pieces: two rooks, two knights, two bishops, one queen, and one king. 
the king's triant 
On one of the triants, sit seven of one player's pieces and two of that player's pawns. This is referred to as that player's king's triant. Six of the spaces, all of the corner spaces and all of the edge spaces, are of that player's color or pattern, and the inner spaces are of the other three colors or patterns. 
Looking at the king's triant with one triant border at the bottom and the opposite vertex at the top, on the edge space at the bottom, initially sits the queen. On the adjacent inner spaces, to the left, initially sits a bishop, and to the right, initially sits a knight. On the corner spaces adjacent to them, initially sit pawns. On the opposite corner space, initially sits a rook. On the inner space adjacent to it, initially sits the king. On the adjacent edge spaces, to the left, initially sits a knight, and to the right, initially sits a bishop. 
the rook's triant, knight's triant, bishop's triant 
On the three triants adjacent to the king's triant, the inner spaces are all of that player's color or pattern. The corner space opposite the king's triant and the two edge spaces closest to it are all of the color or pattern of the other player whose king's triant they are closest to. The corner spaces in the edge row across from the king's triant are of each of the other two colors or patterns, and the edge space between them is of one of those two colors or patterns. 
The triant across the triant border from the edge space that the queen initially sits on is referred to as that player's rook's triant. On the edge space in the rook's triant that is adjacent to that edge space that the queen initially sits on, initially sits a rook. On the adjacent inner spaces, initially sit pawns. 
The triant across the triant border from the edge space that a knight initially sits on is referred to as that player's knight's triant. On the edge space in the knight's triant that is adjacent to that edge space that the knight initially sits on, initially sits a pawn. On the corner space in the knight's triant that is adjacent to the corner space that a rook initially sits on, initially sits a pawn. 
The triant across the triant border from the edge space that a bishop initially sits on is referred to as that player's bishop's triant. On the edge space in the bishop's triant that is adjacent to that edge space that the bishop initially sits on, initially sits a pawn. On the corner space in the bishop's triant that is adjacent to the corner space that a rook initially sits on, initially sits a pawn. 
the antipode triant 
The triant at the opposite end of the spheroid from the king's triant is referred to as that player's antipode triant. The corner spaces are of each of the other three colors or patterns, the edge spaces are of each of the other three colors or patterns, and the inner spaces are of each of the other three colors or patterns. It's the only one of the 20 triants on which none of the nine spaces are of that player's color or pattern; 16 of the 20 triants each have at least one space of each of the four colors or patterns, and only the four antipode triants are missing any space of the opposing color or pattern. Also, 16 of the 20 triants each have at least two spaces that some of the men initially sit on, and only the four antipode triants are missing any space that a man initially sits on. 
USEF@eykoss.com
(All descriptions and illustrations herein are reproduced by permission of and in affiliation with and are copyright 20072023 by the Federation Internationale de Eykoss: Intl@eykoss.com) 9172387904 U.S. Eykoss Federation 10 Minto Court Centereach, NY 11720 http://eykoss.com The U.S. Eykoss Federation affiliates itself with the Fuller Knowledge Alliance. 
