New Method of Calculating CR

[Drawmack]

This is just a thought I had while browsing the forums. A major place where CR seems to break down is in non-standard parties and parties of mixed level. I have an idea on how to combat this problem and figured I'd post it to see what everyone thinks.

What if you based CR on HP instead of Character Level.

The CR system is balanced for an party of ftr, wiz, rog, clr.

So first we calculate the average hp of this party at 1st, 5th, 10th, 15th & 20th level. I'm going to calculate with 12 con.

1st level: 11 + 9 + 7 + 5 = 32
5th level: 32 + 64 = 96
10th level: 96 + 80 = 176
15th level: 176 + 80 = 256
20th level: 256 + 80 = 336

So now we have this (pl = party level)
32 hp = pl 1
96 hp = pl 5
176 hp = pl 10
256 hp = pl 15
336 hp = pl 20

This means that CR 2 - 5 covers 64 hp and each 5 levels after that covers 80 hp.

64/4 = 16 hp per pl levels 2 - 5.
80/5 = 16 hp per level after that. So the break down is this

CR 1: 32 hp
CR2: 48 hp
CR3: 64 hp
CR4: 80 hp
CR5: 96hp
CR6: 112 hp
CR7: 128 hp
CR8: 144 hp
CR9: 160 hp
CR10: 176 hp
CR11: 192 hp
CR12: 208 hp
CR13: 224 hp
CR14: 240 hp
CR15: 256 hp
CR16: 272 hp
CR17: 288 hp
CR18: 304 hp
CR19: 320 hp
CR20: 336 hp

What I'm curious to know is those of you in a party. How would you stack up CR wise on this chart vs. the standard method and do you see any problems with this, besides magic which I already know could be a problem.

 

[MarauderX]

Presently I am in a 3rd level party of four with total HP = 81. Of course I got really lucky and rolled max HP for my bard, but the figher-rogue got two 1's.

I'm not too sure about the HP way of measuring CR, as it also deals alot with the magic and abilities the party has as well. I think CR isn't the best, but it is a good starting point for a DM, although exact XP tends to be awarded arbitrarily anyway for most campaigns I have been in.

 

[Norfleet]

I find the entire CR/experience thing to be messy, so I just wing the experience based on casualty ratios. I find that casualty ratios are the surest method for determining how difficult an encounter was. If nobody was killed or horribly maimed, the encounter can't have been very difficult.

 

[CRGreathouse]

I've found that when estimating CR, the log of the hit points is an important component... but I don't suppose that'll mean much.

http://mwtools.thyle.net/race_gen.html

This uses the fomulae I've come up with; it's a pretty good start for combat monsters. (It doesn't have a good way to rate spellcasters, sadly.)

 

[Norfleet]

That's where casualty ratios come in. You see, no amount of evaluation based on pure stats accurately assesses how challenging something is.

Whether or not something was challenging can be determined only after the fact, by assessing whether or not the contestants were actually CHALLENGED by it.

The easiest means of assessing this, is therefore, to simply count up how many casualties were taken by both sides, and therefore, the casualty ratio.

For example, if 4 PCs go up against 4 monsters, and win, if all 4 monsters are killed, and but 3 PCs are taken out of action, then the challenge level of the encounter was roughly equal to 75% the level of the PCs: a 3/4 ratio. If no PCs became casualties, then the encounter was too easy and is not worth any experience for the encounter itself. If a PC became a casualty more than once during the course of the fight, such as by being taken out of action due to injuries, healed, and then taken out again, count this as 2 casualties.

It is acceptable to count severed bodyparts as multiple kills, as per Vietnam War rules.

 

[CRGreathouse]

Using casulty ratios penalizes PCs for acting tactically.

 

[Norfleet]

No, it doesn't. If players do not act tactically, their casualties will increase, yes, which will temporarily give them slightly more experience for the combat, seeing as they clearly have more to learn from the results of the encounter, such as "Let's not try that again.".

However, they will also quickly become dead at that rate.

Since a group of dead PCs has their character sheets shredded, they start over at level 1.

So, would you rather earn a fair chunk of experience now, and be killed, thereby making it a moot issue, or would you rather earn less experience now, but actually survive?

 

[CRGreathouse]

If I was a player in such a group and my goal was to get to the highest level possible, I'd get lots of healing (cleric, wands, ioun stones, etc.) and choose to play with less-than-sound tactics against anything that wasn't overly dangerous.

Now I'm not in your group, and that isn't my goal-- but I imagine the temptation would always be there. In essence, you're punishing them when they do what's sensible and in-character.

 

[Norfleet]

Well, I never *TOLD* them that this is how I computed experience, and I mentioned in another thread, that you can only be resurrected in the event that you are merely mostly dead, not if you are all dead.

If you haven't yet noticed, which is not unreasonable, since I only recently delurked, I also have a tendency towards house rulings which feature much increased instances of horrible injuries and death, and when I run things, you don't NEED to be tactically bad to have a healthy casualty rate.

If it helps any to visualize, much of the enemy encounter setups I use are inspired by my personal experiences in the Vietnam War.

Are you SURE you want to try something tactically bad just for a few measly XPs, knowing that the reward for accomplishing the mission is worth more than the experience for all of the fights put together, and that the slightest error results in your horrible, gruesome, and likely very permanent demise?