diff --git a/du8/game.c b/du8/game.c
new file mode 100644
index 0000000..e65b83c
--- /dev/null
+++ b/du8/game.c
@@ -0,0 +1,90 @@
+#include "game.h"
+#include "world.h"
+#include <stdio.h>
+
+void init_game(GameState* game) {
+    for (int y = 0; y < 3; y++)
+        for (int x = 0; x < 3; x++)
+            game->board[y][x] = EMPTY;
+    game->current_player = 0;
+    game->game_over = 0;
+    game->winner = 0;
+}
+
+void draw_game(GameState *game) {
+
+    set_message("TicTakToe / Piškvorky", 15, 2);
+
+
+    for (int y = 0; y < 3; y++) {
+        char line[20];
+        int index = 0;
+
+        for (int x = 0; x < 3; x++) {
+            char cell = game->board[y][x];
+            if (cell == EMPTY) {
+                cell = '1' + y * 3 + x;
+            }
+            line[index++] = ' ';
+            line[index++] = cell;
+            if (x < 2) {
+                line[index++] = ' ';
+                line[index++] = '|';
+            }
+        }
+        line[index] = '\0';
+        set_message(line, 17, 4 + y * 2);
+
+        if (y < 2) {
+            set_message("-----------", 17, 5 + y * 2);
+        }
+    }
+
+        if (game->game_over) {
+  if (game->winner == 1)
+            set_message("Game over! Player X won.", 12, 11);
+        else if (game->winner == 2)
+            set_message("Game over! Player O won.", 12, 11);
+        else
+            set_message("Game over! It's a draw.", 12, 11);
+
+        set_message("Press ENTER to restart or Q to quit", 15, 13);
+    } else {
+        char msg[32];
+        sprintf(msg, "Turn of player %c", (game->current_player == 0) ? 'X' : 'O');
+        set_message(msg, 17, 11);
+        set_message("Press ENTER to confirm/Q to quit", 17, 13);
+    }
+}
+
+void handle_input(GameState* game, int key) {
+    if (key >= '1' && key <= '9') {
+        int pos = key - '1';
+        int x = pos % 3;
+        int y = pos / 3;
+        if (game->board[y][x] == EMPTY) {
+            game->board[y][x] = (game->current_player == 0) ? PLAYER_X : PLAYER_O;
+            game->current_player = 1 - game->current_player;
+        }
+    }
+}
+
+int check_winner(GameState* state) {
+    Cell (*b)[3] = state->board;
+
+    const int win_lines[8][3][2] = {
+        {{0,0},{0,1},{0,2}}, {{1,0},{1,1},{1,2}}, {{2,0},{2,1},{2,2}},
+        {{0,0},{1,0},{2,0}}, {{0,1},{1,1},{2,1}}, {{0,2},{1,2},{2,2}},
+        {{0,0},{1,1},{2,2}}, {{0,2},{1,1},{2,0}}
+    };
+
+    for (int i = 0; i < 8; i++) {
+        int y0 = win_lines[i][0][0], x0 = win_lines[i][0][1];
+        int y1 = win_lines[i][1][0], x1 = win_lines[i][1][1];
+        int y2 = win_lines[i][2][0], x2 = win_lines[i][2][1];
+ if (b[y0][x0] != EMPTY && b[y0][x0] == b[y1][x1] && b[y1][x1] == b[y2][x2]) {
+            return (b[y0][x0] == PLAYER_X) ? 1 : 2;
+        }
+    }
+    return 0;
+}