Changes

There are very few differences between playing single-player or multi-player Diablo II. This is not the case in Diablo I. Most obviously, single player Diablo characters are truly single player. They can not cannot play in any sort of MP game. Single player games are saved exactly as they are; all the monsters, level layouts, items on the ground, etc, are preserved exactly. Be sure you save frequently, since if you did didn't you will have to load from the last save point, and it's no fun to have to clear a level for the second time since you forgot to save for the past hour. Diablo does not support nightmare or hell difficulties for single player characters (Hellfire does). There is a work around possible in Diablo, though. If you play a multiplayer game, then exit it and start a single player game, the difficulty of the SP game will be the same as the MP game played before handbeforehand.

Multiplayer Diablo I is equivalent to singleplayer Diablo II. Characters are saved on your computer and can be played solo or with friends in a TCP/IP or LAN game. There are no saved games; just your character's state and the equipment they're using and carrying is saved. There are only 4 [[Diablo Quests|quests]] in multiplayer Diablo I, and the same four are found they occur in every game. Multiplayer is also much harder on Nightmare and Hell, where the monsters have about double the hit points they do in single player. You must be level 20 to create a nightmare game and level 30 to create a hell game.

Another major difference between SP and MP Diablo and Hellfire is level up speed. Multiplayer monsters have more hit points, and are worth far less experience. Characters gain no more than 200 exp/Clvl in MP Diablo or Hellfire (up to 10,000 at level 50), while there is no cap in SP, and each monster in hell can be worth 100,000 and more. A SP character can reach level 44 or 45 in the time it takes to get to level 29 or 30 in multiplayer, and getting an MP character over level 40 requires many dozens more games than it does in singleplayer.