## Help for Entropy

### Introduction

Welcome to the network Entropy server. The rules of Entropy are below. The commands are the same for all pbmserv games.

B5-D3

### IN A NUTSHELL

The game is played with seven pieces per side on a 5x5 grid. The object is to be first to go from the initial position, in which all your pieces can move, to a position in which none can.

```    A   B   C   D   E
+---+---+---+---+---+
1 | x | x | x | x | x | 1
+---+---+---+---+---+
2 | x |   |   |   | x | 2
+---+---+---+---+---+
3 |   |   |   |   |   | 3
+---+---+---+---+---+
4 | o |   |   |   | o | 4
+---+---+---+---+---+
5 | o | o | o | o | o | 5
+---+---+---+---+---+
A   B   C   D   E    ```
`Fig. 1  Starting position`

### THE OBJECT

The winner is whoever disables all his or her pieces first. There is no capture in this game.

### POWER TO MOVE

A piece is enabled to move only when it is in contact, horizontally, vertically or diagonally with at least another piece of the same type. (See the starting position above.) So, if enabled, a piece can move any number of squares in a straight line without jumping over other pieces or changing direction.

### TEAM SPIRIT

Freedom of movement is suspended temporarily if at the beginning of your turn one or more of your pieces is completely isolated (no contact with any other piece, friend or foe.) In this situation you must make a move that reconnects the isolated piece, thus restoring your mobility(*). If it can't be done you must pass. You cannot pass in any other situation.

(*) This is similar to being in check in chess. The difference is that in Entropy it is legal to make a move that puts yourself in check, since you won't have to deal with it until your next turn. (See Fig. 2 below.)

### EXAMPLES

```
A   B   C   D   E
+---+---+---+---+---+
1 | o | x | x |   | o | 1
+---+---+---+---+---+
2 | x | o |   |   | o | 2
+---+---+---+---+---+
3 |   |   | x |   |   | 3
+---+---+---+---+---+
4 | o | x | x |   |   | 4
+---+---+---+---+---+
5 | x | o |   |   | o | 5
+---+---+---+---+---+
A   B   C   D   E
```

Fig. 2  It's Ohs' turn. They have an isolated piece at E5, so their only legal moves are B5-D5 and E2-E4.  Notice that the latter, while not illegal, isn't probably the best move since it creates another isolation at E1.

```
A   B   C   D   E
+---+---+---+---+---+
1 | o |   | o |   | o | 1
+---+---+---+---+---+
2 | x | x |   |   | x | 2
+---+---+---+---+---+
3 | x | o | o |   |   | 3
+---+---+---+---+---+
4 | o |   |   |   | x | 4
+---+---+---+---+---+
5 | x | o | x |   |   | 5
+---+---+---+---+---+
A   B   C   D   E
```

Fig. 3 It's Eks' turn, but they have no way to reconnect the isolated piece at E4, so they must pass.

```
A   B   C   D   E
+---+---+---+---+---+
1 | x |   | o |   | o | 1
+---+---+---+---+---+
2 | o |   | x |   | x | 2
+---+---+---+---+---+
3 | x | o | o |   |   | 3
+---+---+---+---+---+
4 | o |   |   |   |   | 4
+---+---+---+---+---+
5 | x | o | x |   | x | 5
+---+---+---+---+---+
A   B   C   D   E
```

Fig. 4  A final position in which the Eks win.  The isolated piece at E5 is of no consequence because there are no more turns to be taken.