Might and Magic: Gates to Another World Cheats

There's an in-game variable that stores every character's experience points. At some point, this variable maxes out and starts back from zero. If you can make a character have exactly the maximum number of experience points (one more and he/she would have zero), you can keep leveling up forever by continuously selecting to train at the training grounds (you may actually need a rapid-fire joypad if you intend to do this for a long time). If you do this long enough, you'll end up with super characters that have 65535 hit points, etc.

The number of experience points you'll need to do that is way above anything you would ever reach by playing the game normally. The only possible way of earning that much experience is to use the "Loads of money and gems" trick many times, using all of that money to buy experience at:
Lord Slayers Dungeon(Level 1) at 11,5

There are a couple of places (dungeons) in the game where the casting of spells has been disabled to make the game harder to beat. You can overcome this limitation by sleeping. This is especially useful for using teleportation in these dungeons to get to a particular place in seconds!

The road to the Luxus Palace is guarded by Mandagual's Keep, where you need to fight a fairly challenging battle to get past. You can bypass this fight completely by turning around and walking the road backwards; the keep only ''triggers'' if you face it. This allows you to get in the Luxus Palace far earlier and train up low level characters quickly on the Mystic Clowns in the back of the throne room. This same backwards walking trick can be used to bypass various other difficult encounters, but this is probably the most useful spot.