[Grim Tales: Gamemastering] Calculating relative power

[Yair]

I've calculated an encounter with the GT:G pdf and got a challenging but not overwhelming one, but ended up with a TPK. It could be just the throw of the dice, but I'd like to know if I'm at least getting my math right.

The encounter was with a barghest (CR 4), sea hag (CR 4), and 3 Warrior 3 Goblins (CR 2 each?). All were equipped with one potion of CLW and one of CMW; I didn't take that into account, but I reckon at least for the goblins it should be a given.
The party was composed of three level 5 PCs. There was a musket-totting bard, a rouge, and a fire-focused wizard (+2 caster levels for fire spells...). All had probably more equipment than the wealth by level suggests, about 13000 gp I think (not sure on the number).
My calculation went as follows:
Group Power was 3x5^2=75
Opposition Power was 2x4^2+6x2^2=56
56/75=0.745; a tough encounter, but not one I'd expect a TPK of.

The thing that troubles me is that in antoher thread it is said both the DMG and U_K's method predict a TPK. That, makes the whole affair disappointing.

 

[Henry]

Ignoring the CR numbers, there's one thing here:

You've got 5 melee-oriented monsters faced off against a party with three non-melee oriented characters - sounds like the meat-shield ratio was VERY lacking.

Unless the wizard flash-fried the goblins IMMEDIATELY, then this party was in some serious trouble, and even more trouble if the dice rolls turned sour.

 

[Yair]

Ignoring the CR numbers, there's one thing here:

You've got 5 melee-oriented monsters faced off against a party with three non-melee oriented characters - sounds like the meat-shield ratio was VERY lacking.

Unless the wizard flash-fried the goblins IMMEDIATELY, then this party was in some serious trouble, and even more trouble if the dice rolls turned sour.

He pretty much did: fireball on first round took out the hag and three goblins, damaging another one (nearly killing it IIRC).

Still, I should have known better I guess....

 

[Cheiromancer]

Was there 3 goblins, or 6? You say 3, but use 6 in the calculations. And if there only 3 goblins, what was the other one that got damaged?

He pretty much did: fireball on first round took out the hag and three goblins, damaging another one (nearly killing it IIRC).

Still, I should have known better I guess....

So who actually took out the party? The barghest alone?

 

[Wulf Ratbane]

I'm going to assume he meant six goblins.

By the calculations, it's a VERY DIFFICULT encounter. Straight up, that's 75% resources expenditure, with a 63% chance of party survival.

Remember, for reference, a moderate encounter should use only 25% resources! To achieve even that 63% chance of survival, the PCs will have to spend 75% of their resources. That's damn near pulling out all the stops and/or losing more than 2 out of 3 of the PCs.

Unless this was the final battle and the PCs were prepared for it, I wouldn't have used it. Anytime you come up with an encounter that's Very Difficult, just one round of bad die rolls can spell TPK.

To put it back in DMG terms:

2 CR2 goblins are CR4.

That means the group was (barghest CR4) + (hag CR4) + (pair of goblins CR4) + (pair of goblins CR4) + (pair of goblins CR4).

That's five CR4 creatures against a smaller than normal party of CR5 characters. Warning bells should have been going off. The encounter is greater than CR8.

But having said all that, if the wizard managed to kill half the goblins and the hag early in the battle, I am hard pressed to figure out how they managed to end up losing!

 

[Wulf Ratbane]

One last thing:

You performed the calculations correctly, you just interpreted the results wrong!

 

[Rodrigo Istalindir]

One other thing to factor into your situation. I think most calculations fall short in how they deal with the number of characters. It's hard to quantify, but with one less character than the norm, the number of potential actions per round drops, effects that temporarily incapacitate a character are more dangerous, you lose flanking opportunities, etc. The margin for errors or a couple bad rolls is zero.

At lower levels, especially, I would shift most encounters up a category in terms of difficulty with parties of only 3 characters. People that play in groups with gestalt characters notice this a lot.

 

[Yair]

One last thing:

You performed the calculations correctly, you just interpreted the results wrong!

So it seems

About the wizard: well, yes he pulled an excellent fireball on the second round, but by then the rouge was out and the bard was occupied with the barghest....

At any rate, it seems I better not use such a high chi/rho ratio, thanks.

 

[Yair]

Was there 3 goblins, or 6? You say 3, but use 6 in the calculations. And if there only 3 goblins, what was the other one that got damaged?




So who actually took out the party? The barghest alone?

Six goblins, sorry. The fireball was grand, but by that time he was wounded, the rouge was dazed, and the bard occupied by the barghest.
At the end, the barghest alone took out the party but that was after spending several more spells escaping and the attrition of the big fight; it was still CLOSE, the barghest was in one-digit hp when it was all said and done, IIRC.

To summarize: I messed up, too much opposition for my group

 

[GlassJaw]

rogue