Prisoner of the Beginning: One Thousand Years After the Demon King Disappeared

[Western Fantasy DND-like Systemless RPG Adventure] What should I do if I travel to a different world without a system? What should I do if I am even imprisoned? As a qualified Earthling, I need to understand the principle of hugging my thighs. Although I can't do it myself, I have teammates. Although my teammates are not good, I can blend in with the enemy. So said Dick, the Earthling named Dick.