Economists classify goods on a public-private spectrum based on the extent to which they are rivalrous and exclusive. Exclusivity is based on how easily one can be prevented from enjoying a good, and rivalry is based on whether my enjoyment of the good prevents you from enjoying it. National defense is a classic public good: any number of citizens can benefit from it at once, and there is no way to keep someone from enjoying the benefits. Food is a classic private good: we cannot both eat the same bite of food, and there are a variety of ways for me to keep you from eating my food.
Different MMOs place their mobs at different points on the public-private spectrum. In the early days, mobs tended to be rivalrous but not exclusive: whoever got the last hit got the prize, no matter who dealt the most damage, tanked, etc. The reigning solution to the problem was tapping so that you could claim property rights on an enemy, but claiming a camp was a matter of social convention rather than game mechanics. If you tapped the mobs out from under someone, they were yours. Instanced enemies are exclusive. Guild Wars 2 took the unusual step of making mobs mostly non-rivalrous: until the enemy runs out of hp, we can all get all the benefit from it. There is still some rivalrousness in the race to tag enemies or get to the event boss before it falls, but everyone in the fight shares in the fight. [Update: commenters have noted that other MMOs have followed suit to varying extents.]
: Zubon
Interestingly, after Guild Wars 2 had been out for a while, Rift decided to change their system to make their mobs non-rivalrous as well – while the first hitter still gets the loot, anyone who hits it gets XP and, more importantly, credit towards kill-quests. Naturally, you still heard people complain about others “leeching” XP from their kills, but IMO it was a nice improvement.
What would be really nice to see in more MMOs is GW2’s non-rivalrous, non-exclusive resource nodes and quest interactables. It’s really nice to know that I can kill the mobs between me and a node I want with absolutely no possibility that someone else can come along and deprive me of it while I’m busy fighting.
I always enjoy explaining why I consider GW2 a ‘pro-social’ game, especially to people who are not gamers.
“In most MMOs, if you run past someone being mauled by a bear, the polite thing to do is to keep running, or to stand by and watch them be mauled by a bear. If you jump in to help you could end up stealing credit for the kill, so you should leave them to being mauled.
In Guild Wars 2, if you see someone being mauled by a bear, it’s perfectly acceptable to jump in and help them fight it. At the end the bear’s dead, you both get rewards, and you go happily your separate ways.”
During my summer sojourn into Middle-earth I noticed that Turbine had changed things so that as long as you got some damage in on a mob, you got credit. Likewise, I understand WoW now shares credit with whomever tags a major quest mob, though the common mobs remain the same.
I get what you mean when you say “Instanced enemies are exclusive,” in that no one else can come touch your personal instanced copy of it….
…but it also strikes me that instancing enemies in general doesn’t prevent other people from enjoying the fight at the same time. Rather, it may be less exclusive per se and non-rivalrous in the sense that nobody is restricted from access because everybody can generate their own copy of the fight on demand?
If I had to split that hair, I would say that the content becomes non-rivalrous because more than one person/group can experience it with instancing. Each mob within an instance becomes exclusive. The potential pool of total enemies to fight becomes non-rivalrous, but each particular enemy remains rivalrous.