Multiplayplaying with several people, as opposed to Singleplayer, in which only one is playing the game. There are two types of multiplayer for the Diablo series:
- Battle.net, Blizzard's own multiplayer service, which connects players all over the world with each other.
- LAN play through TCP/IP, which allows players to play with each other if their computers are connected in a Local Area Network. (This form of multiplayer was discontinued in Diablo III, which only offers multiplayer through Blizzard's servers.)
The point of Multiplayer is the same as in Singleplayer, defeating the armies of Hell to save Sanctuary. The conditions have changed though, as there are multiple characters in a single game. Since there is no AI behind these players, they are completely unpredictable. Each player can be a potential teammate, a competing hero, or even an enemy. This dynamic nature of real people playing together gives a lot of appeal to the game, since communication is not restricted much. This allows for ordinary smalltalk between players looking to relax and play, but can also allow different players to plan how to approach a game they will play together.
Multiplayer in Diablo III
There cannot be more than four players in a co-op game. Unlike Diablo II, the drop rate or quality of drops will not be affected by the number of people in a co-op game.
Monster Stats Scaling
As was the case in Diablo II, monsters increase their health and damage for each additional player in the game. A hotfix on June 8th was applied that removed the increase in monster damage for Inferno difficulty. The following table illustrates how the scaling differs by difficulty as well: 
|Players||HP %||Damage %||HP %||Damage %||HP %||Damage %||HP %||Damage %|
Multiplayer in Diablo II
The game difficulty adjusts depending on the number of players in the game, which is indicated by the messages: "Diablo Minions grow stronger" or "Diablo's minions grow weaker" whenever a player joins or leaves the game respectively. The hitpoints of monsters, number of drops from monsters and chests, amount of gold dropped, and quality of drops all scale according to the number of players.
The choices for Closed Realm on Battle.net are a bit more numerous compared to Singleplayer mode. Characters going through their creation can be placed into different modes depending on what the player wants to do. The choices are:
Ladder is competitive by nature and will list the top 1000 players in order of experience points to show who is the quickest in leveling. Nonladder removes this competition status with a more subtle approach where level doesn't mean much except to the individual who is playing. Ladder characters get added bonuses in the form of Ladder Runewords. These runewords are some of the most useful runewords in the game, and are only available to Ladder characters. Ladder characters cannot interact with Non-Ladder characters however, which means these runewrods cannot normally be traded outside of Ladder.
Every once in a while, usually when Blizzard releases a new patch for Diablo II, the Ladder is reset. When this happens, all current Ladder characters become Non-Ladder, and players will have to start again with new characters to reach the top of the ranking. However, this process also means that Ladder only runewords become available to regular characters.
Expansion vs Classic
If a player has both Diablo II Diablo II: Lord of Destruction installed, they will be given the option of either creating an Expansion character or Classic character (if the player does not have the expansion, only Classic will be available). Creating an expansion character means that the player get access to Expansion-only features, such as Act 5, the Druid and Assassin classes, among other things.
Hardcore characters only have one life, meaning that if they die, even once, they cannot be played again. Regular characters, popularly called Softcore, respawn in town upon death with no gear, and have to run out in the wild and reclaim their body. They also lose a certain percentage of their accumulated experience upon death.
As one of many warriors, you should cage the beast that is your ego, occasionally. Selfish gameplay is what ruins the game for others, so always use this principle rule from life itself: Treat others as you want to be treated by them. Whether it is sharing items you don't need or helping others out in a tight spot, you can make other people get more out of this game. Its important to remember that this goes two ways. If you are especially helpful towards someone, they may return a favor or two in the future.
Do's and Dont's
- Help where help is needed
- Listen to other people's opinions
- Accept rules of game-creators. Change game if you don't agree with them.
- Share when appropriate. Let tele-chars have some rewards, at least Full Rejuvenations.
- Be polite as much as possible.
- Give others time to invite you. They may be fighting, and incapable to open the party window.
- Be a team player. Protect weaker characters, and support stronger ones.
- Don't spam. Saying things once is enough, twice is ok occasionally.
- Don't be an unthankful git. Common courtesy will boost morale of other players.
- Don't attack people (verbally or physically) for being worse than you. Be thankful you have a better character.
- Don't grab everything. Leave some for others, especially items that you don't need anyway.
- Don't hostile in a current run. People are playing to achieve something, don't spoil it for them.
- Don't BO over another player if his BO is stronger.
- Don't use the same aura if you can turn on another one.
- Don't trick new people. They don't have much, and will be easily discouraged.
- Don't criticize players offensively. They may have reasons for doing things specifically.
- Don't waste all corpses. Some need them to regain live or summon creatures.
- Don't tele in another player's game unless asked.
- Don't walk ahead and run back when you cant beat monsters. You will draw monsters to the whole party.
- Don't knowingly place other's characters in danger.
- Don't hack or bot. It shows that you are weaker than others, for they can beat the game without cheating.
- Don't join a run to do something else, you are taking away a spot that somebody else would gladly take.