I wrote the answer below in response to a question in the MM7 Tavern. I've put the whole answer in because you may need the knowledge if you go on to play MM6-8. Multilooting doesn't apply to MM9, but you can still mephisto the shopkeepers. The bit relevant to you here is in italics."Occasionally in MM6-8, when you loot the corpse of a treasure-bearing monster that you've just killed, the body does not vanish, and you can loot it again. So multilooting is when you kill a monster, then you go up to the body and save your position before you loot it. If the body vanishes, you reload the position and try again until you get something and the body doesn't vanish. Then you save your game, and loot it again. And repeat. And again and again, until you get bored with it. It's most often used with the high-value monsters, such as red, blue or gold dragons, great wyrms, and supreme titans.
Mephistoing is slightly different. It uses the same principle as multilooting in that you save your game before taking an action. For example, you kill a monster, go up to it, and save you game before you loot it. However, this time, you're looking specifically for certain treasures that you want (usually artifacts or relics), and when you get what you want you save your game and go on to the next body. Or when you want a specific item from a shop, you save your game before entering, and if the item isn't in stock, you reload your position and try again."
OK? 
