diff -r 7ffd66591afe -r a298c6637c30 src/game.c
--- a/src/game.c	Fri Mar 28 11:45:01 2014 +0100
+++ b/src/game.c	Fri Mar 28 14:32:52 2014 +0100
@@ -147,19 +147,19 @@
         result = result && !pawn_isblocked(board, move);
         break;
     case ROOK:
-        result = result && rook_chkrules(board, move);
+        result = result && rook_chkrules(move);
         result = result && !rook_isblocked(board, move);
         break;
     case KNIGHT:
-        result = result && knight_chkrules(board, move);
+        result = result && knight_chkrules(move);
         result = result && !knight_isblocked(board, move);
         break;
     case BISHOP:
-        result = result && bishop_chkrules(board, move);
+        result = result && bishop_chkrules(move);
         result = result && !bishop_isblocked(board, move);
         break;
     case QUEEN:
-        result = result && queen_chkrules(board, move);
+        result = result && queen_chkrules(move);
         result = result && !queen_isblocked(board, move);
         break;
     case KING:
@@ -203,10 +203,9 @@
  * 
  * @param board the current state of the board
  * @param move the move date to operate on
- * @return TRUE if the location could be retrieved, FALSE if the location is
- * ambiguous
+ * @return status code (see rules/rules.h for the codes)
  */
-static _Bool getlocation(Board board, Move *move) {   
+static int getlocation(Board board, Move *move) {   
     uint8_t piece = move->piece & PIECE_MASK;
     switch (piece) {
         case PAWN: return pawn_getlocation(board, move);
@@ -215,7 +214,7 @@
         case BISHOP: return bishop_getlocation(board, move);
         case QUEEN: return queen_getlocation(board, move);
         case KING: return king_getlocation(board, move);
-        default: return FALSE;
+        default: return INVALID_MOVE_SYNTAX;
     }
 }
 
@@ -227,9 +226,9 @@
  * @param mycolor the color of the current player
  * @param mstr the input string to parse
  * @param move a pointer to object where the move data shall be stored
- * @return TRUE, if the move is syntactically valid, FALSE otherwise
+ * @return status code (see rules/rules.h for the list of codes)
  */
-static _Bool eval_move(Board board, uint8_t mycolor, char *mstr, Move *move) {
+static int eval_move(Board board, uint8_t mycolor, char *mstr, Move *move) {
     memset(move, 0, sizeof(Move));
     move->fromfile = POS_UNSPECIFIED;
     move->fromrow = POS_UNSPECIFIED;
@@ -331,14 +330,13 @@
         move->piece |= mycolor;
         if (move->fromfile == POS_UNSPECIFIED
             || move->fromrow == POS_UNSPECIFIED) {
-            return getlocation(board, move) && chkidx(move);
+            return getlocation(board, move);
         } else {
-            return chkidx(move);
+            return chkidx(move) ? VALID_MOVE_SYNTAX : INVALID_POSITION;
         }
     } else {
-        return FALSE;
+        return INVALID_MOVE_SYNTAX;
     }
-    // TODO: return status code to indicate the error type
 }
 
 static int sendmove(Board board, uint8_t mycolor, int opponent) {
@@ -366,6 +364,7 @@
 
         if (strncmp(movestr, "surr", buflen) == 0) {
             printw("You surrendered!");
+            clrtoeol();
             refresh();
             net_send_code(opponent, NETCODE_SURRENDER);
             return 1;
@@ -385,28 +384,40 @@
             }
         } else {
             Move move;
-            if (eval_move(board, mycolor, movestr, &move)) {
-                net_send_code(opponent, NETCODE_MOVE);
-                net_send_data(opponent, &move, sizeof(Move));
-                code = net_recieve_code(opponent);
-                move.check = code == NETCODE_CHECK;
-                move.checkmate = code == NETCODE_CHECKMATE;
-                // TODO: record move
-                if (code == NETCODE_DECLINE) {
-                    printw("Invalid move.");
-                    clrtoeol();
-                } else {
-                    apply_move(board, &move);
-                    if (move.checkmate) {
-                        printw("Checkmate!");
-                        return 1;
+            int eval_result = eval_move(board, mycolor, movestr, &move);
+            switch (eval_result) {
+                case VALID_MOVE_SYNTAX:
+                    net_send_code(opponent, NETCODE_MOVE);
+                    net_send_data(opponent, &move, sizeof(Move));
+                    code = net_recieve_code(opponent);
+                    move.check = code == NETCODE_CHECK;
+                    move.checkmate = code == NETCODE_CHECKMATE;
+                    // TODO: record move
+                    if (code == NETCODE_DECLINE) {
+                        printw("Invalid move.");
                     } else {
-                        return 0;
+                        apply_move(board, &move);
+                        if (move.checkmate) {
+                            printw("Checkmate!");
+                            clrtoeol();
+                            return 1;
+                        } else {
+                            return 0;
+                        }
                     }
-                }
-            } else {
-                printw("Can't interpret move - please use algebraic notation.");
+                    break;
+                case AMBIGUOUS_MOVE:
+                    printw("Ambiguous move - "
+                        "please specify the piece to move.");
+                    break;
+                case INVALID_POSITION:
+                    printw("Cannot find the piece that shall be moved.");
+                    break;
+                default:
+                    printw("Can't interpret move - "
+                        "please use algebraic notation.");
             }
+            clrtoeol();
         }
     }
 }