Mushrooms of stoneskin - dungeon junk?

[BlueFish]

Anybody find any conceivable use for those things? Can't imagine ever facing a situation where I'd trade 5 speed for 40 AC.

[BlueFish]

Then again potions of slowness and confusion etc are dungeon junk, so I understand the point (to provide risk in identify-by-use) but I'm still curious as to whether Stoneskin mushrooms were intended to be useful in any way.

[fizzix]

this is actually a good question. Let's see what AC bonus would make stoneskin useful. Specifically what would drop the probability of a hill orc hitting you by half (since you aren't slowed down by more than half, this means fighting hill orcs in a corridor is a net win with stoneskin)

Assume player has 15 AC. Hill orcs hit to hurt (power 40) and they're level 8 so they're hit_roll as calculated by check_hit is 40+(8*3) = 64

Someone recently changed the automatic hit to 12% from 5%, so the probability of hitting is:

[(1 - [(2/3)*AC]/hit_roll)*0.83) + 0.12 = approx 82%

Now to get the probability down to 41% we need an AC of.

AC = [(0.41-0.12)/0.83 + 1]*hit_roll * (3/2) = approx 130

Therefore stoneskin would be situationally useful if the AC bonus was 100 instead of 50.

[Nick]

They might allow you to survive an infestation while you waited for recall to activate.

[BlueFish]

Originally Posted by fizzix

this is actually a good question. Let's see what AC bonus would make stoneskin useful. Specifically what would drop the probability of a hill orc hitting you by half (since you aren't slowed down by more than half, this means fighting hill orcs in a corridor is a net win with stoneskin)

Assume player has 15 AC. Hill orcs hit to hurt (power 40) and they're level 8 so they're hit_roll as calculated by check_hit is 40+(8*3) = 64

Someone recently changed the automatic hit to 12% from 5%, so the probability of hitting is:

[(1 - [(2/3)*AC]/hit_roll)*0.83) + 0.12 = approx 82%

Now to get the probability down to 41% we need an AC of.

AC = [(0.41-0.12)/0.83 + 1]*hit_roll * (3/2) = approx 130

Therefore stoneskin would be situationally useful if the AC bonus was 100 instead of 50.

Interesting, thanks fizzix. That actually coincides pretty well with where I'd have considered using them intuitively. Probably because "100 AC" is my threshold for "good".

One note - the mushrooms increase AC by 40, not 50.

[BlueFish]

Originally Posted by Nick

They might allow you to survive an infestation while you waited for recall to activate.

Ha, good point. But still, never worth the inventory slot, even if potentially useful in very fringe situations.

[buzzkill]

When speed > 10, these mushrooms become more useful, plus their effect seems to last longer.

[BlueFish]

Originally Posted by buzzkill

When speed > 10, these mushrooms become more useful, plus their effect seems to last longer.

The relative speed malus is reduced, but the relative AC increase at the point where players have speed > 10 would also be much less - @ will probably have natural AC of well over 100 at that point.

[Derakon]

Once you're at +10 speed, the enemies you care about are also going to be at at least +10 speed, so taking a -5 hit to your speed is just like being at -5 speed when your enemies are at +0 speed.

...I'm pretty sure that's right, anyway...

The practical upshot is that you need a really compelling reason to accept a speed penalty in this game, pretty much regardless of what your base speed is.

[Timo Pietilä]

Originally Posted by fizzix

this is actually a good question. Let's see what AC bonus would make stoneskin useful. Specifically what would drop the probability of a hill orc hitting you by half (since you aren't slowed down by more than half, this means fighting hill orcs in a corridor is a net win with stoneskin)

Assume player has 15 AC. Hill orcs hit to hurt (power 40) and they're level 8 so they're hit_roll as calculated by check_hit is 40+(8*3) = 64

Someone recently changed the automatic hit to 12% from 5%, so the probability of hitting is:

[(1 - [(2/3)*AC]/hit_roll)*0.83) + 0.12 = approx 82%

Now to get the probability down to 41% we need an AC of.

AC = [(0.41-0.12)/0.83 + 1]*hit_roll * (3/2) = approx 130

Therefore stoneskin would be situationally useful if the AC bonus was 100 instead of 50.

I'd say that is flawed calculus because speed allows you to run away, use spells, missile weapons, healing etc. everything faster. You can't just calculate hit probability and damage and get a result.

I'd say +5 speed has value of >+200 AC, considering that you always have some AC that makes your gaming possible in first place in the dungeon, until you have speeds way greater than your opponents (but even in that case it is not worth to slot, because even then you probably also have more than enough AC as well).

If the AC would reduce also area-effect damage spells (gravity, mana etc. included) then that would be completely different matter. Lets say +100 reduces 25% of all damage and +200 50% of all damage, then having temporary boost of AC would actually matter even with loss of speed.