diff -r f0fc70b6f8f9 -r 2a6d83f4677e src/chess/rook.c
--- a/src/chess/rook.c	Thu Jul 30 18:34:15 2026 +0200
+++ b/src/chess/rook.c	Thu Jul 30 19:17:38 2026 +0200
@@ -30,11 +30,11 @@
 #include "rules.h"
 #include "rook.h"
 
-bool rook_chkrules(Move *move) {
+bool rook_chkrules(const Move *move) {
     return move->torow == move->fromrow || move->tofile == move->fromfile;
 }
 
-bool rook_isblocked(GameState *gamestate, Move *move) {
+bool rook_isblocked(const GameState *gamestate, const Move *move) {
     
     if (move->torow == move->fromrow) {
         int d = move->tofile > move->fromfile ? 1 : -1;