The Challenge with Challenge Ratings

[3Power]

I recently began a D&D 3.5 game set primarily in the underdark. I had DM'd two games before but both were relatively low level. Tired of playing a low level game, I had this new game start off with everyone at level 6. However, I have been running into trouble... My encounters are just not providing the Challenge Rating the books say they should be. Case in point, the party is now level 10. I sent three Dread Harpoon Spiders from MM3 after them, all CR 9. Now, the whole point of the harpoon spider is that it harpoons enemies, but it only has +7 Attack bonus? That will never hit my players ACs which are for the most part just short of 30 at the moment. Meanwhile, they have no trouble hitting the spiders' 19 AC. The end result is that the players end the encounter in two rounds, doing something like 70 damage each on their turns. And then one time, I sic 5 Giant Alligators on them, and several party members nearly die from their +11 Bite attacks despite being CR 4. I just don't get it. I've tried just sending tougher encounters at my players, but there isn't much different most of the time. They defeat them just as easily and then get the inflated XP award. My players have leveled up in a single session.

So does anyone have any advice or alternate CR systems I could use? The players are having fun, but there doesn't seem to be any challenge happening here.

[Z3ro]

One of the things I learned about the CR system early in my DMing career is that the system takes no account of your party's relative abilities when referencing monsters. This is especially true with regards to the pure numbers, such as saves, AC, and to-hit bonuses.

My best advice is simply look at those bonuses relative to your players. As you mentioned, a +7 just isn't going to cut it against 30+AC. Either up the attack bonus some how or send different monsters against the PCs. This can be done for any strategy you want to employ; you should have most if not all of the PC's stats ahead of time. You can use these to tailor encounters much closer to the challenge level you are looking for, rather than the arbitrary ones WotC set.

[Runestar]

There is something very wrong with the cr of the huge spider. The 5HD one is just cr4, and using the MM advancement rules, improving it to 9HD should raise its cr to just 6, not 9. I believe this to be a typo. This also means that while a single spider is likely a fair fight for a group of 5th - 6th lv PCs, it does not necessarily mean 3 are a fair encounter for a 9th lv party, because monster effectiveness tend to degrade rapidly as your group becomes stronger. Their cr assumes you pit 1 foe against a standard party.

I agree that cr is more of an art than a science, and more often than not, you need to pay attention to your PC's stats to determine what they can or cannot face.

Also, if you are going to send multiple weaker foes, I think it is okay to be less conservative about the final EL and let it be 1-2 higher than than the party's level. You can also mix and match foes, not just to add variety but also to shore up one another's weaknesses. For example, instead of just throwing 4 hill giants (EL11), you could replace 1 hill giant with a drider, who can prebuff everyone with haste, while supporting them with debuffs like suggestion, dispel magic, glitterdust and ray of enfeeblement.

For the next challenge, maybe try something like a fire giant + raksasha combination (EL12)? The giant is buffed with bull's strength, endurance, haste. While he wades into combat, the raksasha hangs back and blasts the party with fireballs spells (which the giant is immune to), while being protected by mage armour and possibly shield.

You get the idea. :smalltongue: