Monsters, Challenge Ratings, and Encounter Balance in RPGs

 

It's a quirk of the modern RPG scene that there is so much concern over "Balance". It really falls into two areas - 1) Character Balance and 2) Encounter Balance. It's almost an obsession in some corners of the internet and while bouncing back and forth between various Supers RPG and running a D&D style campaign I thought it was worth discussing here. We did Characters yesterday so let's talk about Encounters.

Thinking back to the beginning early D&D didn't really care about encounter balance - the most we saw there was making sure a given dungeon level had monsters that matched that level which meant that it should be appropriate for characters of that level. Other early RPGs really didn't address much beyond this either. Runequest, Gamma World, Traveller, and Star Trek were all pretty light here. The idea mostly was "well, here is the setting, here are some potential opposing forces, drop your characters in and see what happens." There was also an assumption that your players knew to run when things got to hot and that might even require some extra effort like throwing out rations to distract pursuing monsters or having the chief engineer make some warp drive engineering roles to push the ship above it's normal maximum.

Later we get to D&D 3E and we first start to see encounter balance as a concept introducing challenge rating and encounter level as part of the game. I don't think this is a bad idea but I think it's doomed to  disappointment much of the time as one tries to codify a certain mix of hostile capabilities versus a generic player character power level. 

This is from the 3.5 DMG. Find the encounter level you want on the lefthand side, then decide how many creatures you want in the encounter moving to the right and it will show the CR you need to aim for to create a balanced encounter. Theoretically anyway.  

This is the Troll statblock from the 3.5 MM. Now trolls aren't particularly complex most of the time - though in this edition you could give them class levels and that could get weird fast. The only complication here is their regeneration - it's ignored by Fire and Acid. This version was a little more complicated but later editions have it so that taking any fire damage in a round shuts off the Trolls regeneration for that round - period. So if your party has a bunch of fire or acid type attacks then the troll's regen effectively does not exist. Challenge rating is affected by special defenses so the reason this guy is a "5" is at least partly because of that. Maybe if you ignore his regen he should only be a "4", maybe even a "3" which immediately wrecks the math, especially if you have a group of them. Considering in later editions wizards get fire bolt as a standard attack power, clerics get sacred flame, and flaming oil isn't hard to come by you can imagine this is not a particularly difficult thing to overcome. It's come up a lot in my current campaign and so I discount the rating for trolls a bit as they are effectively just like an ogre for the most part. Even one character landing a fire attack that round means all of the other characters normal attacks "stick" - just like any other monster. This is the kind of thing you have to do as a DM to keep these numbers relevant. 

I mean, he shouldn't be happy about this ...

This also ignores things like terrain, light conditions, weather, etc. There's a big difference between encountering something in  set of 10' wide corridors vs. out in the open country.

So taking these kinds of systems on faith is a mistake - if you really care about this stuff. I'd say 4E D&D did the best job with its math but even then I had to eyeball a fair amount of things. I did love the process of determining what kind of area this was, what kinds of encounters would be present, using the numbers to build an encounter and then tuning it up for my party - it was a great way to organize setting up a ruined city waiting to be plundered. 

Ultimate balance ...

But once you go outside of the D&D-O-Sphere there just isn't much like this approach. For point based systems (mostly supers for me) you could use the points but mostly you just use the power caps (active point limits/power  levels) as a guideline. There's no larger framework though for calculating numbers for multiple opponents vs. party size. A few examples:

•    Looking at some superhero games there just isn't much math. 
• Icons is great talking about creating adventures and campaigns but doesn't burn any pages discussing encounter math.
• The Sentinel Comics RPG covers a lot of this as well and does talk about timing and challenges - the Green-Yellow-Red thing is important here - but it doesn't get into "enemy math" either.
• The M&M main book doesn't talk about numbers at all - it discusses encounters as part of an adventure or how they fit into a villainous plot. The Gamemaster Guide though, actually has a few paragraphs on balancing encounters and actually does mention power levels - every 2 PL increase means they are roughly twice as powerful so a PL12 villain is a good fight for two PL10 heroes. That's as far as the math goes.
• The Marvel Multiversal game is one of the newer entries and while it does have a page and a half on balancing encounters the only number advice in the entire section is to put your players up against opponents of the same tier - of which there are six. 
• Beyond strict superhero games entries like Savage Worlds have no real encounter guidelines. The only notes are that some creatures are wild cards but the game doesn't stick ratings on it's monsters beyond that.
• Star Wars!
• FFG Star Wars mentions that when using multiple opponents they should be a die or 2 lower on their abilities. That's about it.
• d20 Star Wars, Saga Edition specifically here assigns a challenge level number to every monster/npc entry in the game and this is used to determine both encounter balance and XP awards. Not terribly surprising with it being heavily 3E/4E based.
• d6 Star Wars - 2E Revised and Expanded in this case - has no time for encounter balance. The designing adventures section talks about pacing, different types of encounters, and "making it Star Wars" but does not put any numbers on opponents or award XP based on that kind of things. 
• The Trinity Continuum system has no encounter guidelines either. There are levels of threat as in minor-major-colossal, etc. and there are caps on their dice pools for each given level but there is no corresponding link to what level of character experience is an even match for that. There is a fair amount of material about adventure or story design but it's largely math-free.

I hope those are mostly minions ...

The one thing that many of these systems do is provide a two to three-tiered framework for opposition with normal opponents, minions or mooks, and then maybe some kind of master level opponent that is stronger than normal and possibly designed to take on multiple PC's. Mooks, almost universally, are designed as massed opponents that drop out of a fight with a single hit.  That can give a different flavor to a combat encounter and saves the GM a lot of work. Bosses tend to get extra actions or some kind of fate points to help them mitigate bad rolls or to guarantee success. Saving the complexity for the medium to boss level encounters helps a lot in running a game while letting the players feel like they are accomplishing something. 

Not a minion!

So this emphasis on encounter balance and the numbers associated with tracking and measuring that is pretty much a D&D thing. Other games don't worry about it much if at all. The only game that definitely has one on this list is the version of Star Wars published by the D&D people. Why don't more RPG's use this kind of approach? I will close with a paragraph from the M&M 3E Deluxe Gamemaster's Guide that I think sums up my feelings on it really well: