diff -r 02c509a44e98 -r 41017d0a72c5 src/chess/rules.c
--- a/src/chess/rules.c	Wed Jun 11 16:54:20 2014 +0200
+++ b/src/chess/rules.c	Mon Jun 16 13:45:31 2014 +0200
@@ -44,6 +44,22 @@
     return simulation;
 }
 
+void gamestate_init(GameState *gamestate) {
+    memset(gamestate, 0, sizeof(GameState));
+    
+    Board initboard = {
+        {WROOK, WKNIGHT, WBISHOP, WQUEEN, WKING, WBISHOP, WKNIGHT, WROOK},
+        {WPAWN, WPAWN,   WPAWN,   WPAWN,  WPAWN, WPAWN,   WPAWN,   WPAWN},
+        {0,     0,       0,       0,      0,     0,       0,       0},
+        {0,     0,       0,       0,      0,     0,       0,       0},
+        {0,     0,       0,       0,      0,     0,       0,       0},
+        {0,     0,       0,       0,      0,     0,       0,       0},
+        {BPAWN, BPAWN,   BPAWN,   BPAWN,  BPAWN, BPAWN,   BPAWN,   BPAWN},
+        {BROOK, BKNIGHT, BBISHOP, BQUEEN, BKING, BBISHOP, BKNIGHT, BROOK}
+    };
+    memcpy(gamestate->board, initboard, sizeof(Board));
+}
+
 void gamestate_cleanup(GameState *gamestate) {
     MoveList *elem;
     elem = gamestate->movelist;
@@ -587,7 +603,7 @@
     }
 }
 
-int eval_move(GameState *gamestate, char *mstr, Move *move) {
+int eval_move(GameState *gamestate, char *mstr, Move *move, uint8_t color) {
     memset(move, 0, sizeof(Move));
     move->fromfile = POS_UNSPECIFIED;
     move->fromrow = POS_UNSPECIFIED;
@@ -612,7 +628,7 @@
         if (!move->promotion) {
             return INVALID_MOVE_SYNTAX;
         } else {
-            move->promotion |= gamestate->mycolor;
+            move->promotion |= color;
             len -= 2;
             mstr[len] = 0;
         }
@@ -629,7 +645,7 @@
             move->piece = KING;
             move->fromfile = fileidx('e');
             move->tofile = fileidx('g');
-            move->fromrow = move->torow = gamestate->mycolor == WHITE ? 0 : 7;
+            move->fromrow = move->torow = color == WHITE ? 0 : 7;
         } else {
             /* move (e.g. "Nf3") */
             move->piece = getpiece(mstr[0]);
@@ -664,7 +680,7 @@
             move->piece = KING;
             move->fromfile = fileidx('e');
             move->tofile = fileidx('c');
-            move->fromrow = move->torow = gamestate->mycolor == WHITE ? 0 : 7;
+            move->fromrow = move->torow = color == WHITE ? 0 : 7;
         } else {
             move->piece = getpiece(mstr[0]);
             if (mstr[2] == 'x') {
@@ -701,12 +717,12 @@
     
     if (move->piece) {
         if (move->piece == PAWN
-            && move->torow == (gamestate->mycolor==WHITE?7:0)
+            && move->torow == (color==WHITE?7:0)
             && !move->promotion) {
             return NEED_PROMOTION;
         }
         
-        move->piece |= gamestate->mycolor;
+        move->piece |= color;
         if (move->fromfile == POS_UNSPECIFIED
             || move->fromrow == POS_UNSPECIFIED) {
             return getlocation(gamestate, move);