Summoner Cheats

In multi-player mode, max out your bow skills and magic
resistance. Then go to last level, the one during winter. Run
straight through both levels. Because of a glitch, only two or
three monsters will follow you. Because you can run faster than
any of the monsters in the levels, you will not get hurt. Make
sure you know the way through the levels. When you get to the
last level in Lenele with the final Boss, stand back and attack
him with your bow. He will only use magic, and if you have maxed
magic resistance nothing he casts can hurt you. Every time you
kill him, you will gain a level and get most of the good items
from him, such as the Assassin's Crossbow and the Sword Of Summoners
(under the hard difficulty setting). You can do this until you
reach the last level and sell most of his items for a lot of gold.

Hold down the left shift and the tilde keys, and click on the ground to be instantly teleported there. however you have to click on a fairly flat piece of ground that you could normally walk to.
this works in battles, paused or unpaused, as well, but it won't work while travelling on the world map.
this works on all versions of the game.