Multiplayer

More is fun.

The multiplayer game is what the design team feels is the core of Diablo III. They are designing D3 to be most fun in cooperative play with a friend, PvM party, and creating game features to function best in that setting. Gold is shared, items aren't fought over since each character only sees the items they can pick up, party joining is streamlined, in-game hostility is removed, and more.

The Party System

There is no more party system in D3, at least not like there was in D2. In D2 players who joined a game were neutral, neither friend nor enemy. They could become enemies by clicking the hostile button, or become friends by joining a party together. Once they were partied, they shared experience and gold. Partying was optional though, and parties could be dissolved or abandoned.

In D3 there is no more party system, since the hostility option has been removed. (There will be dueling and PvP in special games for that purpose, but it's not going to be an option in regular, PvM games.) The D3 Team found that it was pointless to have a additional party system menu with invitations and joining required, so they simply removed that option. All players in the same PvM game in D3 are in the same party, by default.

Maximum Party Size

The D3 Team has not yet committed to a maximum game size for Diablo III. The issue is still open to debate, but the developers have said 4 or 5 characters will likely be the maximum. This is a drop from the 8 allowed in Diablo II games, and it's entirely due to gameplay, rather than technical issues.

D3 could allow 8 or 16 players in a game, but in playtesting the team found that more than 4 or 5 was too many. More characters didn't fit easily onto the screen, the spell effects were too visually-overwhelming, the party split into two or three groups, and the general play experience was degraded.

Jay Wilson quoted from the game's debut press conference. [1]

Though the team hasn't decided how many people will be in a group, Wilson said to expect four to five players.

Jay Wilson, from Blizzcon 2008, on October 17, 2008: [2]

Q: Is four people multiplayer games set in stone?

A: It grows more and more set all the time. In Diablo 2, eight player games are very uncommon, and they wouldn’t be in the same party or the like and we have just found that it’s not as fun as with four people. We have the ability to set any number we want, but four seems to work out very well.

Kevin Martens and Julian Love, from Blizzcon 2009, August 2009: [3]

Kevin Martens: For the maximum number of players in a game, we're going with 4 now. That's how many you can have on the games on the show floor. That's not final, and we'll keep looking at it during development. On PvP, we're going to do more on that, but we're not really showing any of our ideas yet. We're more focused on co-op at this point, and we want to make people play together more. The loot drop is one example. Now when loot drops the first pass on items is all for you, and only if you pick things up and put them in your inventory, then drop them, can your friends see them or pick them up. Also on multiplayer, the code's very good already and very smooth, and we will keep it that way all through development. The multiplayer is very fun and we're going to keep it at the highest possible polish.

Julian Love: The important part about how many people can play together is not technical limitations. It's about how many is fun. How many effects are going off, how much chaos is on the screen. Our testing is trying to find the sweet spot for those considerations. We have fantastic programmers, and technology has come a long way since Diablo 2, so we're not limited on that front.

• For a detailed discussion of the pros and cons of maximum party size limits, check this recent On the Drawing Board article.

No More Hostility

One big change to multiplayer games in D3 is that there is no nonconsensual hostility. There will be dueling and PvP in special games for that purpose (no details have yet been revealed), but there is no way to "go hostile" in a regular PvM game.

The D3 Team is aware that some method will be required to control or remove or avoid grief causing players (who could spam the game, or lead monsters to trap waypoints, or other annoying behaviour, even if they can't actually go hostile or be gone hostile against), but they've offered no suggestions about that yet. It might be possible to boot players from a game by majority vote, or the game creator might retain that right, but we'll have to wait to see what solution the team offers up.

PvP

There will be PvP play in Diablo III, but not in normal games. PvP will exist in special games, arenas or dueling games that the team has not yet released any details about. See the PvP article for more details.

Individual Item Drops

A major change/improvement to party play in Diablo III is the fact that items will no longer be fought over. Characters in D3 only see items that they can pick up; there's no more ninja looting teleporting Sorceresses, no more melee specialists grabbing all the goodies, etc. In D3 when items are dropped, they can only be seen by the character who can pick them up. Most normal monsters will only drop one (if any) items, and drop rates per player should be about the same as they were in D2, although on the whole more items will fall. Boss monsters will drop multiple items each time, so that every player in the game gets something.

It's not yet determined how much item drops will be customized; in theory a Barbarian might find a wand and an orb, while the Witch Doctor got an axe and heavy plate armor. Or the D3 team might make drops more appropriate for the character who sees them; no class-specific items for other classes would drop for your character, for instance. As of BlizzCon 2008, the D3 team talked about item drops being randomly distributed, so there might not be any customization of appropriate drops at all.

One key to this system is that while dropped items can only be seen by the character they are dropped for, any item dropped by a character can be seen by all other characters. Jay Wilson has often mentioned the phenomena of players reaching a certain point on a level when everyone's inventory is becoming full. By tacit agreement, all the players pause for a moment and drop all of their unwanted stuff in a sort of free yard sale, allowing each other to pick through the stuff and take whatever they might want.

The Importance of Multiplayer

Here is a quote on Multiplayer development by D3 Lead Jay Wilson:

AG: I know that in StarCraft 2, a lot of the development was focused around multiplayer - a lot of the game design and the development being done was on multiplayer first. Is that something that you guys do with Diablo as well, or is a bit more focused on the single-player or a bit of a mix?

Jay: For us it's a little bit more focused on the singleplayer, it's not quite the same as StarCraft. I've played RTS before and I've seen people do it both ways and I seem to prefer the method where you work on multiplayer first, because you're really establishing the core game mechanics.

For us, a lot of the core game has actually come out of singleplayer, but what we've done along the way, is we've always had cooperative play enabled. So people play cooperatively all the time. Any time anything does work for cooperative play we fix it right away. So any mechanics that don't work, any kind of balancing or tuning that needs to be done, we try to do it simultaneously for both – but we do focus on single-player more.