Discussion about Heroes I.

And if possible, tell me, is the tournament map completely open from the start, or can it simply be opened using a cheat, achieve the desired moves against the opponent, and then, by saving at the end of the day, successfully close it?

During a "clean" playthrough, using cheats in any version of the game is, of course, prohibited, but during preliminary testing, players usually reveal the map and observe the AI's behavior, etc.
I know that in Heroes 1, there is a single cheat to reveal the map (enter 101495 directly in the game), but if you do this, you won't be able to save and play as if it were a "legitimate" game, because the map cannot be closed at the end.