Back up your original save (rename it SaveData_old.dat).
Replace the existing save file with the downloaded one (ensure the filename matches exactly). Yu-gi-oh Power Of Chaos All Cards Save Game
Launch the game — all cards should now appear in your trunk. Back up your original save (rename it SaveData_old
For Power of Chaos, the "All Cards" save is widely accepted even among long-time fans. Why? Because the game lacks a multiplayer mode. Once you beat the final boss (Yugi/Kaiba/Joey), the only fun left is experimenting with wild combos—which requires a full collection. The save file doesn't harm anyone else's experience. Replace the existing save file with the downloaded
Crucial Note: These are standalone games. A save file for Yugi will not work for Joey. Download the save specific to your installation.