Frogcomposband mechanics questions

[Saru]

Picked up frog a couple months back, and have accrued a large number of questions I've been meaning to ask, so I'll just dump them here I apologize if the list gets really long or rambly. Thanks in advance!

1. Is there a formula to calculate the probability of a monster saving against a given spell based on the spell's `power` and the monster's level? I know that more power = better, but that's about it.

2. Similarly, how does player saving throw work internally? is it similar to V where you can get 100% resist, or is it based on the monster's spell `power` as well?

3. Is there any use for the various statues of enemies I find? I know figurines give pets, but haven't found a use for statues. I thought maybe they'd give you full monster memory of that monster somehow, but haven't been able to test it yet.

4. How much does slow monster slow the monster?

5. How does monster stunning work? Do they have increasing levels of severity like the player, or is it just duration based flat debuffs? And what kind of penalties exactly does stunning inflict on the monster? same as V?

6. For staves of confusing lights, do all the status effects have the same odds of being saved against, or are some easier than others? I've consistently gotten a power 160 or 200 staff to stun and terrify target creatures, but the slowing and stasis appears to happen much less, especially against tough enemies like archliches.

7. How do I deal with monsters using dispel magic on me? Do I ever get a saving throw, or is it just their way of saying 'ha ha you suck now'

8. How do vampiric weapons work, especially when they have other brands as well? Do I heal the full damage dealt from all blows, or just a portion?

That's all for now, I did try to hunt through the source code for answers to a few of these but it gets complicated really fast. I'd appreciate it if someone with a bit more experience with frog could help me. Thanks!

[Sideways]

1. Is there a formula to calculate the probability of a monster saving against a given spell based on the spell's `power` and the monster's level? I know that more power = better, but that's about it.

To some extent it depends on what the spell does, as the Confusing Lights answer below shows. There is a "standard" monster save (which compares the monster's level, boosted for uniques, against the player's level, sometimes boosted by a bonus from on a relevant stat) but many effects have their own individual saves that may depend on the effect's power, the player's level, both or something else. A fairly common power-dependent save (used by for example Slow) is monster level vs. 1d(power-10)+10.

2. Similarly, how does player saving throw work internally? is it similar to V where you can get 100% resist, or is it based on the monster's spell `power` as well?

The saving throw formulas can vary slightly depending on the situation, but the most basic is that you have a X% chance of saving where X is your saving throw, multiplied by 100, divided by 100+Y where Y is a boost that depends on the monster and situation. Most commonly Y equals the monster's level divided by 2.

The Free Action save formula is similar but slightly different (it rolls a random integer between 0 and (100+Y-1) and compares it to your saving throw). That save gets called once for every pip of Free Action you have unless you have enough (2 against low-level monsters, 3 against high-level monsters) to be completely safe.

In situations where no monsters are involved the calculations can also vary, but most commonly your saving throw needs to be higher than a random integer between 0 and 99.

3. Is there any use for the various statues of enemies I find? I know figurines give pets, but haven't found a use for statues. I thought maybe they'd give you full monster memory of that monster somehow, but haven't been able to test it yet.

There is currently no use for statues (other than selling if you play with selling on). The idea of a class or monster-race that would actually use statues for something has been suggested a couple times, but not yet implemented.

4. How much does slow monster slow the monster?

Slow Monster gives the binary -10 slow. It is possible for monsters to be incrementally slowed in other ways.

5. How does monster stunning work? Do they have increasing levels of severity like the player, or is it just duration based flat debuffs?

They have increasing levels of severity like the player. Stunning increases the monster's spell fail rates and decreases the monster's accuracy and damage output in melee.

6. For staves of confusing lights, do all the status effects have the same odds of being saved against, or are some easier than others? I've consistently gotten a power 160 or 200 staff to stun and terrify target creatures, but the slowing and stasis appears to happen much less, especially against tough enemies like archliches.

Yeah, they all have their own calculations. The stun from Confusing Lights, I think, is actually a direct stun with no save at all, it only checks stunning resistance (but monsters do get saves against most other sources of stunning).

7. How do I deal with monsters using dispel magic on me? Do I ever get a saving throw, or is it just their way of saying 'ha ha you suck now'

Psions can resist it, and the One with Magic demigod talent gives you a save against it; other than those, you'll just have to recast the buffs you really need after being dispelled.

8. How do vampiric weapons work, especially when they have other brands as well? Do I heal the full damage dealt from all blows, or just a portion?

It's only a portion, and it's limited, usually to 50 HP per turn. (Most other vampiric effects give full healing, but not weapons.) Vampiric brands generally work independently of other brands, though they're also just on/off, so having multiple things that all make your weapon vampiric doesn't make the vampirism any stronger.

[Saru]

Thanks for the quick reply and helpful answers @Sideways! I'd almost convinced myself that some of the higher leveled monsters were immune to slowing despite it not saying so in their description. Still, slow is better than I thought if it is a full -10, so I guess I'll keep spamming my confusing lights staves.

[Sideways]

Thanks for the quick reply and helpful answers @Sideways! I'd almost convinced myself that some of the higher leveled monsters were immune to slowing despite it not saying so in their description. Still, slow is better than I thought if it is a full -10, so I guess I'll keep spamming my confusing lights staves.

Uniques are immune to slowing, also monsters who are immune to everything (babbles, spellwarp automatons), but no one else is.

[Saru]

I have a clevel 49 mage, Armageddon/Sorcery;

casting slow monster from the second sorcery book on a demilich (monster level 54 according to probing)

(54 vs 1d88 + 10), which means I should have a 50% chance of slowing the monster, but after 7+ castings the lich remains unslowed. Is there something else to the formula I'm not seeing, like a bonus to the monster's level? All the total has to do is be higher than the monster's level right?

I've accepted that I'm simply doing the math wrong somehow, but can't for the life of me think of what else to do.

[Sideways]

I have a clevel 49 mage, Armageddon/Sorcery;

casting slow monster from the second sorcery book on a demilich (monster level 54 according to probing)

(54 vs 1d88 + 10), which means I should have a 50% chance of slowing the monster, but after 7+ castings the lich remains unslowed. Is there something else to the formula I'm not seeing, like a bonus to the monster's level? All the total has to do is be higher than the monster's level right?

I've accepted that I'm simply doing the math wrong somehow, but can't for the life of me think of what else to do.

That is actually a problem with the game itself, thanks for bringing this to my attention. The code used by this particular spell (and some other single-monster Slow Monster effects) computes a power (here 98) but then ignores it completely and uses the player's CL instead. I will need to fix that.

Mind you, during any given game, it will happen many times that 7 consecutive coin-flips all go wrong

[Saru]

Hmm, this bug doesn't affect the slow power from a stave of slowing or confusing lights though, right?

And I know that I could have just been really unlucky that time, but that was only the latest in a series of tests.

Thanks again for answering my questions and taking the time to look at this.

All the other power based spells, eg mass stasis are unaffected by this, correct?

[Sideways]

Hmm, this bug doesn't affect the slow power from a stave of slowing or confusing lights though, right?

Right.

All the other power based spells, eg mass stasis are unaffected by this, correct?

In the development version, yes. There are slightly similar (though technically completely unrelated) issues with confusion in the last release version, although they generally don't make confusion unexpectedly weak the way slowness was for you. It is possible there's still some other oddball spell somewhere else with problems like this, but if so, it would be something much rarer and class- or realm-specific.

[Saru]

OK thanks for all the clarification! I'll post here if I have any more questions / weird interactions.

[Saru]

Strategy advice?

Traversing down Angband to grind for loot on the bottom few levels. DLevel 85 I get a random quest to kill 'Nodens, lord of the great abyss', or something like that. I've attempted to kill him 4 or 5 times, escaping only because of 0% fail teleport level. I managed to get probing off on him, and he looks and feels to be nearly impossible for my clevel 50 mage to even touch.

Globe of invulnerability is useless, since he has both psycho spear and dispel magic, and worse, he casts *extra intelligently* it feels like. Every haste I put up is instantly dispelled, as well as him favoring his nearly 500 dmg manastorm heavily. The most I've gotten him down to was 6 stars before having to bail. At this point I'm at a loss. Any tips? I don't want to intentionally fail the quest since that hurts fame, but if he's as impossible as I think he is then I may as well. Thanks in advance!

[Sideways]

Nodens is probably the single deadliest monster in the game. I have killed him a few times, but it's never really safe.

In theory, you can use the (expensive) Trump level-teleport service in Morivant to skip the Nodens quest entirely without failing it; it's a bit cheesy but, hey, Nodens is a special case.

If you do want to fight him (and risk instant death to an unlucky double-manastorm) I would suggest using your biggest offensive spells, !restoremana/clarity, and Teleport Away any time you're in trouble and/or need more time to regain mana in (you should have zero-fail Teleport Away, and Nodens doesn't resist teleportation... though many of his summons will). Also helps if the angel uniques are dead. Nodens is a passwaller, which I usually try to use to my advantage when I fight him; stay in a convenient location and wait for him to approach. Avoid areas that might allow Nodens to snipe you from around a corner (even if you have telepathy), and be extremely wary of tele-self since Nodens telefollows.

Like I said, though, being anywhere near him risks instant death to an unlucky double-manastorm... The problem isn't that you can't kill him but that he will very likely kill you first, unless you have enough HP (and enough spare !*healing*...) to reliably survive a double-manastorm.

[CyclopsSlayer]

One question I've had for a long time is with Ninjas.
(admittedly this test was back under PCB but the core should/could be similar)
When attacking from hiding there are several possible messages that the game produces. 'Hack', 'Slice' etc... I turned on the damage display to see if I could correlate slicing someone in half doing more or less than a hack or whatever.

The damage ranges displayed led me to believe there is either a vast randomizer or that the messages were merely color. I recall a hit near 1000 damage, that the same message also displayed 20ish.

It seems that only the first strike gets the Hide Critical and later hits are normal, unless the mob tries to run and then the normal hits become Backstabs.

So, do the various messages mean anything, or is a Hide Crit just a Hide Crit?
As well, what does Backstab do?

[Sideways]

There are three types of ninja critical with some similarities; the code calls them "backstab" (for hits against sleeping monsters), "fuiuchi" (for hits from the shadows, so this is the 'hide crit' proper) and "stab fleeing" (for hits against fleeing monsters). Each has a different message; backstab is "You cruelly attack so-and-so", fuiuchi is "You make a surprise attack, and hit so-and-so with a powerful blow" and stab fleeing is "You attack so-and-so in the back."

They all have slightly different effects, though with many similarities. All of them multiply the dice; backstab by between 3 and 4.5 (depending on CL), fuiuchi by between 2.5 and 3.5 (again depending on CL) and stab fleeing by 1.5. Rolling a backstab or fuiuchi critical happens before the accuracy check and (almost) guarantees that you won't miss. All three make that particular hit more likely to roll a critical injury, and backstab and fuiuchi make a hit much more likely to hit a fatal spot or roll a fatal injury.

Critical injuries and especially fatal injuries/hits on fatal spots are responsible for the most outrageous ninja criticals, almost certainly including that 1000-damage hit you remember. They can occur on normal hits, but as noted, they're more likely when you attack from the shadows or backstab a sleeping enemy.

[Saru]

Finally!

http://angband.oook.cz/ladder-show.php?id=23677

Just thought I'd post my first win! @Sideways thanks for the advice for skipping Nodens through Morivant. I definitely would have died to him because of my stubborn refusal to fail any quests. If anyone has any race / realm combos for a spellcasting class, I'd appreciate some inspiration! Leaning toward grey mage, but we'll see.

Edit: I've meant to ask, what do rune swords do? 0d0 (-10, -10) and unenchantable seems like the most worthless item of all time. There must be something to them, maybe only for certain classes like rune knight?

[Sideways]

Edit: I've meant to ask, what do rune swords do? 0d0 (-10, -10) and unenchantable seems like the most worthless item of all time. There must be something to them, maybe only for certain classes like rune knight?

Rune swords gain strength from killing monsters (especially uniques), and can become quite deadly over time. They also pick up some fairly serious downsides, though; because of that and how slowly they develop, many players do consider them useless, but there have been a few rune sword wins.