Welcome to the network Cradle server. The challenge command is described here. Other commands are the same as for all pbmserv games.

cradle challenge [-size=n] [-all_shapes] [-num_each=n] **userid1** **userid2 [userid3]**

Starts a new game between **userid1** and **userid2** (and optionally **userid3**).

The -size option specifies the board size (default is 2 triangles per side).

The -all_shapes option specifies that any of the three base shapes described below may used each turn, not just the cradle.

The -num_each option specifies the maximum number of each shape that can be used (default is unlimited).

Cradle is a simple puzzle game in which players pack pieces into a hexagonal box. The last player able to place a piece wins.

The board is a hexagon tessellated by triangles. Players have access to an unlimited number of pieces called * cradles*, which are polygons formed by four triangles, as shown.

a b c d e f g

+-----+-----+

4 / \ 4

/ \ + +

+ + + + / \ / \

3 / \ 3 / \ / \

/ \ + +-----+ + . . +-----+

+ + + + + \ / \ a . . /

\ / \ / \ . b . /

2 \ / 2 +-----+ +-----+

+ + + +

\ / A cradle.

1 \ / 1

+-----+-----+

a b c d e f g

Each turn the current player must place a cradle on the board, possibly stacked on top of existing pieces, aligned with the board's triangular grid but otherwise oriented as they wish. The cradle must sit flat and be supported at all of its corners; either of the central triangles (marked 'a' or 'b' above) may sit over empty space, but not both. The cradle cannot exactly cover the four triangles of an existing cradle.

Cradles must be lowered down onto the board from above. They cannot be slid in sideways to fill gaps below overhangs.

The last player able to place a cradle wins the game.

The following example shows a completed game; no more cradles can be placed on this board to sit flatly supported. The number shown on each component triangle indicates its height.

a b c d e f g

+-----+-----+

4 / / 2 / \ 4

/ / 2 / 1 \

+ +-----+-----+

3 / / 3 / \ \ 3

/ / 3 / 2 \ \

+-----+ +-----+-----+

\ 1 \ 3 \ 1 1 /

2 \ 1 \ 3 \ 1 / 2

+-----+-----+-----+

\ 1 / 2 / /

1 \ / 2 / / 1

+-----+-----+

a b c d e f g

Notes

Games on the small board are quick and typically last less than a dozen moves; they are puzzles as much as games. For a deeper game, use a larger board (say size 4) or the additional shapes described below.

The cradle is one of three shapes that can be made from four equilateral triangles, such that each triangle exactly shares an edge with at least one other:

+ + / \ / \ +---+ +---+---+ +---+---+ +---+---+ / \ / \ \ / \ / \ / \ / \ = / \ / \ / +---+---+ +---+ +---+---+ +---+---+ Triangle Cradle Snake (L) Snake (R)

Use the -all_shapes options to use all of these shapes in a game, not just the cradle. The Triangle must be supported flatly at each of its three corners (its central triangle may sit over space). The Snake must be supported flatly at each of its two ends (both of its central triangles may sit over space). Note that the Snake may be turned over to change the directions of its triangles.

Games played with the -all_shapes option will last longer than the standard game and be harder to finish. For instance, there are three places at which a Snake can be played in the above example to continue the game.

Six of each shape can be packed onto separate levels as follows:

+---+---+ +---+---+ +---+---+ / \ / \ / \ \ / \ \ + + + + +---+ + + + +---+---+ / \ / \ / \ / / \ / / \ \ +---+---+---+---+ + +---+---+ + + + +---+---+ \ / \ / \ / / \ / \ / / / + + + + + + +---+ + +---+---+ \ / \ / \ \ / \ / / +---+---+ +---+---+ +---+---+

Two of each shape can be packed onto a single level as follows:

+---+---+ / \ \ + +---+---+ / \ \ \ +---+---+ + + \ / / / + +---+---+ \ / / +---+---+

The fact that levels can be completely filled means that games can go on indefinitely if both players conspire to do so. To avoid this, a "must reduce" rule can be used: any placement that results in exact coverage of the level below is not allowed. Each higher level will therefore reduce in size and the game will converge to a quick solution.

A winning strategy may exist for either player on the small board using only cradles (probably the opening player), however this strategy is not yet known.

If the -num_each option is used, the game ends in a tie if all of the pieces run out before a winner is found. Players are therefore under extra pressure to force a speedy conclusion as the piece limit approaches.

Use the "-all_shapes" and "-num_each=6" options to simulate a game with six of each type of piece.

**Note:** Unlike most other games, Cradle is a game of restriction and is much better played on the smaller board. If a larger board is used, it is recommended that only the single cradle shape be used. If multiple shapes are used then a fixed limit *must* be set.

Each move describes the coordinates of a shape's four component triangles:

cradle moveboard# userid passwordb1,c1,d1,d2---- places a shape with triangles atb1, c1, d1andd2

Cradle rules copyright (c) Cameron Browne, May 2007.

"Cradle" would probably have been called "Chevron" if the ASCII board display favoured triangles rotated at 90 degrees (i.e. vertical edges rather than horizontal ones).

Implementation and help file by Cameron Browne, May 2007.