Critical Mass for an MMO and Cross Server PUGs

How many people do you need to have online at the same time in a MMO? Up until now, this has been determined mostly through technical requirements (how many people can one server support?). But depending on design, some MMOs need more people online at the same time than others otherwise they just don’t work.

If you look at WoW with it’s plethora of solo content, popular 5 man instances, and battlegrounds that you can jump into without being in a pre-made group, it’s very clear that server population can get quite low and people will still be able to play. So although your chances of being able to run a 5 man instance of your choice in the middle of the night are lower than at primetime, you still only need 4 other people to do it. The only big sticking point is raiding, and battlegrounds themselves – and just as cross-server battlegrounds eased the need for one server alone to provide all participants, it will probably ease the need for single server raid PUGs too.

Warhammer, by comparison, seemed from the outset to be a game that was designed for a truly massive population. Open world PvP split across lots of different zones and different level bands needed quite a lot of players on the same server to all be interested at the same time if fights were to be consistently available (in practice, there were so many different zones that player warbands could comfortably avoid combat while taking forts). Public quests, while fun, needed to have enough people in the same zone interested in the same quest to get the group together. It was never the case (except maybe in the very early days) that you could just wander around and happen on a group in the public quest you wanted to do.

So I always wondered if at any point the devs had sat down and tried to figure out their critical mass. ie. how many players do we need per server for there to be a reasonable chance that a player can find a public quest/ scenario/ open world pvp/ instance to do at prime time/ off peak daytime/ night? I’m sure they didn’t.

Note: In game economies are a different issue. They do require a certain number of active players, but those players don’t all need to be online at the same time.

Raising the Critical Mass

So there are some design decisions that will raise the critical mass of a game and spread the existing player base:

  1. Non scaling content that needs large numbers of people (ie. raids of fixed size, battlegrounds of fixed size)
  2. Larger group size.
  3. Lots of group content spread all across the level range
  4. Lots of levels, and lots of content that is level specific (ie. difficult to group with people outside your current level range)
  5. Wide choice of group content (eg. lots and lots of public quests)
  6. Very large world with long travel times (ie. once you have found people, how difficult is it to get the group together)
  7. Highly tuned content. (ie. people reluctant to run it with people they don’t know or in PUGs.)

So in general, the more choices people have about what group content to do, the more people you need to have online to raise the chances that other people will also want to do it.

Lowering the Critical Mass

Likewise, other design decisions will lower the critical mass of a game, and funnel existing players together:

  1. Have people from all timezones on the same servers (means people who play offpeak from one timezone are more likely to find other players)
  2. Good LFG channel and functionality
  3. Robust PUG scene. (ie. an atmosphere where people feel encouraged to join random groups)
  4. Announcements when public quests become active (ie. to funnel people towards them)
  5. Reward systems that funnel people towards specific group content (ie. daily dungeon rewards)
  6. Lots of solo or small group content
  7. Scaled encounters. Lots to do for different group sizes.

Is cross-server PUGs the answer?

Just from looking at those lists it’s easy to see that WoW is specifically designed to work fine with a lower player population. This seems ironic given how much more popular it is than other MMOs, but I do think it is one reason for the game’s massive success. It really is much easier to log in and just play.

On the other hand, the high critical mass design statements lead to a wider, deeper, larger game. I would rather PLAY that game, but … as soon as the critical mass dips too far down, you lose many of the advantages. More and more I believe that just as Wolfshead suggested, better scaling is the answer.

Is it possible to have the best of both worlds? It might be that in WoW, the cross-server PvE PUGs that are coming next patch will be more game changing than anyone yet guesses. Surely it will be easier to find groups for those lower level instances when you have several servers contributing to the player pool. And if PUGs for raids are implemented across server also, who knows where it could end?

Not only that, but the game retains the current server size so people who like their current server communities won’t feel swamped as they move around the game world. They’ll just have access to a much larger group of players to instance with.