Help me with the CR system

[The Mormegil]

One of my gaming groups is adamant in wanting to play 3.5 (or 3.P doesn't really matter to us). I'm going to DM that, and I remember how it went back in the day... with terror.

What I really really dread is the CR system, and encounter planning. I'm looking for advice on how to handle that. Or homebrew fixes or something, I don't know. I just want a reliable way to plan an encounter that's not too hard or too easy without having to spend 3 hours on it.

Specifically, I have a problem with the following:
1) More than one enemy kinda breaks the system. Larger groups especially. You can't be sure how putting together monsters will impact the encounter's difficulty.
2) Caster monsters tend to provide a much higher challenge for their rating. Buffs can make their allies too strong for their level, at will magical abilities often break the system too (the Ice Wall spam...).
3) Templates break the system (broken templates are especially egregious).
4) Class levels break the system. HD advancement often breaks the system. The end results are unpredictable and often off scale.
5) Using NPCs often breaks the system. This is due to the highly volatile character creation.
6) Gear breaks the system. There are no real guidelines on how it works.
7) Changing the base sheet of the monster (like adjusting feats or even skills) can break the system. Adjusting the feats of a troll can easily make it a LOT harder to beat while it should still be CR 5.

The above can be avoided if need be by abiding to the "single monster of appropriate CR" paradigm (plus avoiding casters), which frankly sucks. However...

8) CR is very dependent on the party. The same creatures can provide very different challenges to different groups. Preparation also plays a huge impact.
9) CR isn't a good reflection of danger. Bodak encounters are a lot more dangerous than Treant encounters even though the CR is the same.
10) CR isn't a good reflection of monster power. Compare an Ogre Mage (at-will invisibility, flight, darkness, change shape, regeneration, a 9d6 cone of cold and much more) to a treant (+2 AC, +30 hp, -1 melee damage, almost useless trample, no range, useless DR, vulnerability to fire). Same CR, but one is clearly more powerful than the other (unless you can get the drop on them, in which case both are pretty much dead before they can act).


Also, is PF significantly better than 3.5 in this regard? Their monster database is not as large (probably a plus) and the XP budget seems a good step forward. I never tried it though.

Also, any good advice to avoid rocket tag gameplay?

[Eldariel]

PF CR has less of WotC goof-ups but Paizo stepped up with some of their own; e.g. PF Tarrasque (http://www.d20pfsrd.com/bestiary/monster-listings/magical-beasts/spawn-of-rovagug/tarrasque) is supposedly CR 25 even tho a well-built level 20 Fighter can solo it, to say nothing of a spellcaster. I feel PF gives players more toys in basic character builds so I'd prefer it. CR-wise, well, just don't bother with CR.


Really, it's not too hard; the trick is just remembering the numbers the PCs seem to be hitting, and their tactics (and the encounter location). You can then judge if a creature e.g. autohits them and kills (probably a bit tough for most creatures), how fast they can probably deal with it (how are its saves, HP, AC and immunities) and how lethal its special abilities are.

And really, EL = party level is basically a non-challenging fight unless enemy has circumstances on their side. A single enemy loses 'cause PCs have 4 actions to its one, and 4 enemies lose 'cause they're individually so much weaker as to not be a serious threat.

That said, the DMG has a good listing of how hard you'd want to keep your encounters in general; a good rule of thumb is, a small portion should be unwinnable in a straight-up fight (e.g. PCs encounter an old Dragon - negotiate, run, avoid it are usually how it goes tho of course, Great Wyrm probably has more important things to do than killing every human it detects) which forces them to keep options other than "kill it" in their mind. Then some should be tough, some should be average and some should be easy (lets the players feel the growth of their power). And some should be tough/impossible unless the players can figure the enemy out (enemy spellcasters and many puzzle monsters like Hydras can be made to fit this mold).

[Telonius]

Sometime back in the early Stone Age, Vorpal Tribble came up with a rough CR estimator. This may help you.

Just in general, CR is as much an art as a science. An encounter that would be trivial for one group might be deadly for another, and vice versa, so a certain amount of guesswork is going to be involved. Some parties are going to use horrible tactics and awful builds, some won't have characters filling the "classic roles," and sometimes the dice decide to suddenly commit treason. But for an "average" group, I've found this gives a pretty close estimate.


#1. Divide creature's average HP by 4.5 to 6.5.
4.5 for 5 HD or lower, 5 for 6-10 HD, 5.5 for 11-15 HD, 6 for 16-20 HD., 6.5 for 20-25 HD.

#2. Add 1 for each five points above 10 its AC is, subtracting 1 for every 5 below.

#3. Add 1 for each special attack (+2 to +5 or more if its got a decent number of spells in its spell-like abilities).

#4. Add 1 for each quality unless you deem it worthy of more. Add 1 for each resistance and 10 points of DR it has, and 2 for each immunity. Subtract 1 for each vulnerability.

#5. Add 1 for every two bonus feats it has.

#6. Divide total by 3. This should be its rough CR

[Yawgmoth]

Here's how you work with CR:
Ignore it entirely.
Look at your party's numbers, what their AC, +hit and +saves are specifically.
Take the fluff of the monsters you like and let them hit the average AC on a 10 and have DCs of the total average save +10. Adjust +/-(1-5) depending on how terrifying you want the fight to be.
There, monster design tailored to your game in 5 minutes.