diff -r 41bbfd4d17a3 -r 824c9522ce66 src/chess/rules.h
--- a/src/chess/rules.h	Mon Mar 31 14:08:00 2014 +0200
+++ b/src/chess/rules.h	Mon Mar 31 15:03:25 2014 +0200
@@ -68,6 +68,7 @@
 
 typedef uint8_t Board[8][8];
 
+
 typedef struct {
     uint8_t piece;
     uint8_t fromfile;
@@ -80,6 +81,20 @@
     _Bool capture;
 } Move;
 
+typedef struct MoveList MoveList;
+
+struct MoveList {
+    Move move;
+    MoveList* next;
+};
+
+typedef struct {
+    Board board;
+    uint8_t mycolor;
+    MoveList* movelist;
+    MoveList* lastmove;
+} GameState;
+
 #define POS_UNSPECIFIED UINT8_MAX
 #define mdst(b,m) b[(m)->torow][(m)->tofile]
 #define msrc(b,m) b[(m)->fromrow][(m)->fromfile]
@@ -102,6 +117,8 @@
 #define fileidx_s(c) (isfile(c)?fileidx(c):POS_UNSPECIFIED)
 #define rowidx_s(c) (isrow(c)?rowidx(c):POS_UNSPECIFIED)
 
+void gamestate_cleanup(GameState *gamestate);
+
 /**
  * Maps a character to a piece.
  * 
@@ -126,29 +143,28 @@
  * Evaluates a move syntactically and stores the move data in the specified
  * object.
  * 
- * @param board the current state of the board
- * @param mycolor the color of the current player
+ * @param gamestate the current game state
  * @param mstr the input string to parse
  * @param move a pointer to object where the move data shall be stored
  * @return status code (see rules/rules.h for the list of codes)
  */
-int eval_move(Board board, uint8_t mycolor, char *mstr, Move *move);
+int eval_move(GameState *gamestate, char *mstr, Move *move);
 
 /**
  * Validates move by applying chess rules.
- * @param board the current board state
+ * @param gamestate the current game state
  * @param move the move to validate
  * @return TRUE, if the move complies to chess rules, FALSE otherwise
  */
-_Bool validate_move(Board board, Move *move);
+_Bool validate_move(GameState *gamestate, Move *move);
 
 /**
  * Applies a move and deletes captured pieces.
  * 
- * @param board the current board state
+ * @param gamestate the current game state
  * @param move the move to apply
  */
-void apply_move(Board board, Move *move);
+void apply_move(GameState *gamestate, Move *move);
 
 #endif	/* RULES_H */