One of the innovations that recent editions (by recent, I mean in the last few years) of Dungeons and Dragons brought to the table was the concept of Challenge Ratings (CR) in games. This is a tool by which a Game Master can assign a CR to a group of PCs, based on their classes and levels. All the monsters also have a CR. So when designing a scenario, if you keep the CR of the monster groups close to the CR of the player group, then hopefully they will get some kind of an appropriately challenging fight.
If you want them to have an easy fight, you pick monsters with a much lower CR. If you are adapting a bought scenario, you can see easily where you might need to adjust the CR to be appropriate for your players. It isn’t always spot on — Challenge Ratings don’t take everything into account — but it’s a start. You can even assign a different CR to a monster if a specific class is or isn’t in the player group.
In MMOs, one of the big challenges facing any group leader is deciding which encounters are appropriate for their group. Can we run a heroic? Which is the easiest heroic? We have a lot of melee, which instance works best with that? We have an inexperienced tank here, where can we go that will help his confidence but still reward everyone? What instance is good for our level range?
It’s no accident that one of the biggest threads on the WoW tank forums is usually some variant of ‘Am I ready to tank X?’
But isn’t this something that the game could just as easily tell us?
Right now, a lot of the knowhow to answer these questions is learned from experience. In fact, being good at estimating appropriate targets for a group is one of the key leadership skills in game. But in order to do it well, you need to know the content inside out, and the capabilities of every class, and it helps if you also know the players. That’s not at all casual friendly.
One of the reasons that PUGs in WoW are getting notoriously fussy with respect to checking people’s gear and achievements is because of the lack of Challenge Rating. If you aren’t confident in your ability to rate challenge and you’re dealing with players you don’t know, the easiest way to gauge your group is via hard empirical evidence. Since people tend to be risk averse in PUGs, the ratings they require are often way way above what the content actually demands.
So how could challenge ratings work
As a start, rate all instances on a scale to reflect their difficulty. Initial difficulty can be based on some balanced group (1 tank, 1 healer, x dps) with an average level of gear below the average level of gear that drops in the instance. ie. let’s assume that your baseline group actually wants the drops for upgrades.
After that, let the challenge ratings float to reflect which groups actually do complete the instance. Clearly gear levels tend to increase over time so it’s important not to just average it, but it’s worth knowing if any specific classes are favoured or disfavoured for those encounters. Or let players rate the instance and take that into account also.
Of course Blizzard know how many groups complete each instance. But why shouldn’t that ‘perceived difficulty’ rating be available to players too.
Assigning a challenge rating to player groups is harder. You can never guarantee that any group can complete any encounter, you don’t know the players. But you can advise on which might be a good shot or where they could look for upgrades. You can compare the average gear level with the gear levels of other groups who have successfully beaten the instance.
If they can put the work into matching player teams via arena ratings, surely they can think up something for PvE also.