diff --git a/src/main/c/VierGewinnt.h b/src/main/c/VierGewinnt.h
index 6ec2043..a52d6cd 100644
--- a/src/main/c/VierGewinnt.h
+++ b/src/main/c/VierGewinnt.h
@@ -3,3 +3,17 @@
 
 #define ROWS 6
 #define COLS 7
+
+void initializeBoard(char board[ROWS][COLS]);
+void printBoard(char board[ROWS][COLS]);
+int isColumnFull(char board[ROWS][COLS], int col);
+int dropPiece(char board[ROWS][COLS], int col, char player);
+int checkWin(char board[ROWS][COLS], char player);
+int checkHorizontal(char board[ROWS][COLS], char player);
+int checkVertical(char board[ROWS][COLS], char player);
+int checkDiagonalLR(char board[ROWS][COLS], char player);
+int checkDiagonalRL(char board[ROWS][COLS], char player);
+void showMessage(const char* messageColor, const char* message);
+void showInvalidInputMessage();
+void showColumnFullMessage();
+void showWinMessage(int player);