Wands of Slow Monster are awesome

[Derakon]

My current character has now managed to take down Brodda, Wormtongue, Orfax, Boldor, and Ufthak without any issues whatsoever, because after one or two zaps with his Wand of Slow Monster, they've been tossed down to Very Slow.

Is this desirable? If not, what is desirable? If early uniques should be slowable (and I don't see why they shouldn't be) how hard should it be to slow them, and how long should it take them to recover? And how much should they be slowed by? By way of comparison, when the player gets slowed (as my half-troll rogue, with his 26% saving throw, does so very depressingly often), it typically lasts only for maybe 5 turns, and the speed reduction is a flat -10.

Looking at the code, wands of Slow Monster have a flat power level of 50 (thus, monster slowing should last about 50 turns...I think, though AFAICT there's no place where the monster's speed is restored when the timer runs out). They should also only reduce speed by 10, but seem to be doing so by more than that, even after only one zap.

There's zero dependence on the player's magic device skill. This seems like a clear opportunity to make wand power scale with skill level.

[Philip]

Mages with both the sleep monster and the slow monster spell are also awesome. As soon as I start running out of mana I can sleep a monster, rest up, slow him and start magic missleing.

[Derakon]

I'm gonna go out on a limb and say that Wands of Slow Monster are buggy. I hit Lugdush with one once and he started moving one turn in five (EDIT: which works out to 1 in 3 after considering my 1.6 blows/round...so that just matches the "very slow" I was noting earlier). That's insane. I don't understand how this is happening since, from my reading of the code, it should only be possible to slow a monster once, and that only by -10. So something screwy's going on here.

[Magnate]

I'm gonna go out on a limb and say that Wands of Slow Monster are buggy. I hit Lugdush with one once and he started moving one turn in five (EDIT: which works out to 1 in 3 after considering my 1.6 blows/round...so that just matches the "very slow" I was noting earlier). That's insane. I don't understand how this is happening since, from my reading of the code, it should only be possible to slow a monster once, and that only by -10. So something screwy's going on here.

I agree that this is buggy. We need to look at the duration as well as the amount of slowing that's going on. I've opened ticket #1482 for this.

[takkaria]

Looking at the code, wands of Slow Monster have a flat power level of 50 (thus, monster slowing should last about 50 turns...I think, though AFAICT there's no place where the monster's speed is restored when the timer runs out).

I don't remember quite where it's done, but monsters definitely should speed up again (I remember testing that it happened fairly recently).

[Derakon]

I don't remember quite where it's done, but monsters definitely should speed up again (I remember testing that it happened fairly recently).

I think I was misreading the code. There is a line to restore the monster's speed. Still, 50 turns of Very Slow is excessive.

[Magnate]

Ok, here's the code for slow monster:

} else if (idx == MON_TMD_SLOW) {
        if (v) {
            if (m_ptr->mspeed < r_ptr->speed - 10) {
                m_note = MON_MSG_UNAFFECTED;
                resisted = TRUE;
            } else {
                m_ptr->mspeed -= 10;
            }
        } else {
            m_ptr->mspeed = r_ptr->speed;
        }
    }

That means a monster can get to -20 speed after two successful zaps. That does seem a bit powerful. We could of course make it easy for them to save, but that quickly renders the spell junk. I'd rather the save was reasonable (are they failing too rarely at the moment?) and both the power and duration were toned down a bit. Changing the above to -= 5 would be a good start, and reducing the duration too. The code is too tangled for me to understand where the numbers 100 (slow monster) and 50 (slow monsters) come from - they seem arbitrary.

EDIT: some further investigation suggests that low-level monsters must be failing their saves an awful lot, due to an error in my fix for #1427. Ho hum. But the 50- or 100-turn duration of slowing predates my changes (and perhaps was intended to be balanced with monsters saving almost every time). I think halving both the duration and the speed penalty would be a good start.

EDIT2: ok, I just pushed a fix to staging which improves monster saves, reduces the duration of slowing to 20 turns and halves the speed penalty. But it seems to be buggy: -5 is now halving the monster speed, so this means Derakon was not going mad when he said the original code (-10) was making the monster move once in four or five moves. Stay tuned.

[Derakon]

Monsters don't seem to resist all that often. I don't think any of the uniques I fought resisted more than once before succumbing. As for the numbers, the 50 comes from the defined effect for MON_SLOW; it's in the call to project(...GF_OLD_SLOW...), IIRC. I don't have the code with me just at the moment to double-check, sadly.

[buzzkill]

When I slow something, I expect it to be moving at half speed (in most cases, or -10 by in PC terminology). Please don't change this.

If you want to limit the maximum slowing to -10, I fully support it. I always found it odd that slowing stacked.

I assume uniques get a extra save or something vs. slow/confuse/sleep. I don't want (all) uniques to be immune, but I do want to have to burn half a dozen charges before one takes.

[Derakon]

I suspect that the problem here is that -10 in that code doesn't actually mean "half speed"; there's probably some weird interpretation of that speed value that's causing -10 to mean "one third speed". That's a bug. The fact that monsters are so easily slowed is another.

[Magnate]

I suspect that the problem here is that -10 in that code doesn't actually mean "half speed"; there's probably some weird interpretation of that speed value that's causing -10 to mean "one third speed". That's a bug. The fact that monsters are so easily slowed is another.

I've changed it to -5, and that seems to be exactly half speed. It shouldn't be, but that's how it's playing in staging. So that's ok then.

I've also upped the saving throws a little - let me know if it's still not enough. Yes, uniques get a second save, so slightly more than twice the chance of saving.

I've also reduced the duration from 50 to 20. That's long enough to be useful without being uber. Again, let me know how it plays once it's in the next RC.

[Antoine]

I've changed it to -5, and that seems to be exactly half speed. It shouldn't be, but that's how it's playing in staging. So that's ok then.

I've also upped the saving throws a little - let me know if it's still not enough. Yes, uniques get a second save, so slightly more than twice the chance of saving.

I've also reduced the duration from 50 to 20. That's long enough to be useful without being uber. Again, let me know how it plays once it's in the next RC.

Could other wands (devices, spells) have the same problem?

How was the problem introduced? (is the best fix to simply revert the original behaviour)?

A.

[Magnate]

Could other wands (devices, spells) have the same problem?

You mean doubled effects? I don't think so - I think the problem is specific to speed. Specific to slowing, in fact - since hasted monsters correctly move at double speed.

How was the problem introduced? (is the best fix to simply revert the original behaviour)?

I don't know. The problem is that slow monster has been so useless for so long, it's hard to tell how long the problem has been around. It could be ancient (though having said that, the most likely candidate is the introduction of the MON_TMD_ system in ~January).

[Timo Pietilä]

I've changed it to -5, and that seems to be exactly half speed. It shouldn't be, but that's how it's playing in staging. So that's ok then.

Is it directly energy? -5 energy is half the normal speed 10 energy. Then normal speed monster would practically stop with -10.

[Derakon]

Is it directly energy? -5 energy is half the normal speed 10 energy. Then normal speed monster would practically stop with -10.

Which is why I don't think it could be directly energy. My experience is pretty consistent: hit the monster with the wand once, they start moving at 1/3rd normal speed. The "one in five" I reported earlier was simply because I was in melee at the time and using a weapon that gave 1.6 blows/round.