Automatic pricing quirks

[Pete Mack]

Ok, thanks for the opinion. Can I just confirm that you value ESP at 40 damage per blow, 200 damage per round? You're prepared to give up that much damage to have ESP? That's what "2x fire immunity" means at the moment.

The answer is: yes. There are plenty of weapons that do pretty good damage, so I'm willing to lose some melee in favor of ESP. (I don't know how many times I've walked around with a Blessed {ESP} weapon, with another weapon for swap.)

...this takes us back to the other thread about desirability vs. rarity. You're talking about having prices affected by rarity - which is fine, but is not currently part of the algorithm. Perhaps it should be an additional component of price.

Not quite: desirability is affected by rarity as well as usefulness. So RBase isn't all that expensive because it's common, even though it's critical. ESP and speed(!) are all that much more expensive because they are both critical and rare.

WRT the fixed bugs, I'll update to the latest. You must be pretty busy--my build is only a couple days out of date.

[PaulBlay]

Are items with penalties going to be sold officially or is that just till the code is refined a bit more?

If you keep them I suggest you sell them as

Long Bow (X3) (-2, -3) {bargain bin}

[Pete Mack]

On further thought about rarity and usefulness: Perhaps the way to think about this is:
how many times in a game do you discard speed boots or source of ESP. (Not many, and a lot get left in storage.) How many times do you simply ignore a 200 dam/turn weapon? Dozens.

[Magnate]

On further thought about rarity and usefulness: Perhaps the way to think about this is:
how many times in a game do you discard speed boots or source of ESP. (Not many, and a lot get left in storage.) How many times do you simply ignore a 200 dam/turn weapon? Dozens.

Not quite. The correct comparison (for your value of ESP) is how many times do you discard or ignore a ring of damage +40? Not many.

WRT updates - yes, I spent a chunk of Good Friday anticipating exactly those posts!

[Pete Mack]

@magnate
But a Ring of Damage +40 simply doesn't exist (or has rarity 2^-25 ?). The only thing remotely similar is a branding ring, which I might ignore many times in a game.

Somebody needs to get a Nobel prize in game-pricing, so we can do this right.

[Magnate]

But a Ring of Damage +40 simply doesn't exist (or has rarity 2^-25 ?). The only thing remotely similar is a branding ring, which I might ignore many times in a game.

But that's the point! We're trying to test a system whereby things are valued and priced according to equivalent damage.

I was wrong though - I forgot that off-weapon damage is worth twice as much, since it adds to any weapon. So your evaluation of ESP is equivalent to a +20 damage ring, which is perhaps about right. The current rating is only that of a +10 damage ring, which is definitely too low. You probably wouldn't ignore a +20 damage ring any more often than you'd ignore a source of ESP. I do fear that doubling the value of ESP will make it very unlikely to appear on randarts though, so I suspect 60 power (= +15 damage ring) might be a useful compromise.

There are all sorts of difficulties with trying to calculate prices (instead of just reading them in from the text files) - the game wasn't designed for it and we're trying to retrofit an algorithm. It's good to do some testing and refine what we have.

On the rarity point, it would be nice if we could just multiply the calculated price by k_ptr->alloc_prob, but ego item rarity is a whole lot more complex than that. I'm still wondering how to make low-pval speed boots more expensive without breaking everything. I'm not sure it's possible, as with integer arithmetic we really only have two choices of pricing (linear or quadratic), and linear just doesn't work (neither does cubic). Hmmm.

[Pete Mack]

But that's the point! We're trying to test a system whereby things are valued and priced according to equivalent damage.

I was wrong though - I forgot that off-weapon damage is worth twice as much, since it adds to any weapon. So your evaluation of ESP is equivalent to a +20 damage ring, which is perhaps about right. The current rating is only that of a +10 damage ring, which is definitely too low. You probably wouldn't ignore a +20 damage ring any more often than you'd ignore a source of ESP. I do fear that doubling the value of ESP will make it very unlikely to appear on randarts though, so I suspect 60 power (= +15 damage ring) might be a useful compromise.

I agree with the +15 damage ring being about equivalent. And I think that the damage model approximates a cost based on both rarity and "importance".

I figure immunity might be worth giving up about 6-8 damage from a ring. The elven rings are so valuable because they combine so many features from a single source, not because of the immunity alone.

[Magnate]

I agree with the +15 damage ring being about equivalent. And I think that the damage model approximates a cost based on both rarity and "importance".

I figure immunity might be worth giving up about 6-8 damage from a ring. The elven rings are so valuable because they combine so many features from a single source, not because of the immunity alone.

Yes, and the power calculation now adds extra power for lots of things being found on one item (low resists, high resists, sustains, pvals and misc abilities all attract extra power if there are lots of them) - so items combining lots of good stuff (like the elven rings) are now rated properly.

Fire immunity is currently rated the same as a +10 damage ring (20 damage/blow on a weapon), i.e. 2/3 as much as telepathy. This seems about right - in pure value terms it may only be worth 6-8 damage on a ring, but it's quite a bit rarer than ESP (as it's not found except on artifacts), so +10 reflects this additional rarity.

[Pete Mack]

Nexus undervalued. Or: stat gain is broken

Another quirk: Nexus is severely undervalued in the current environment.
Until I've got a very good saving throw, I'm unwilling to go without nexus resistance.
Three things contribute to this:
1. Stat potions are somewhat more rare, because objects as a whole are more rare.
2. Stat gain requires more potions (not counting the move from 18/9x to 18/100.) Previously, you could get +2 in the initial stat gain then big chunks up to 18/70.
3. Stat gain after base 18 is no longer compressed. Previously you could rely on getting from 18/00 to 18/70 fairly quickly. Now it takes as long as getting from 11 to 18. Since the difference in power is also greater, getting swapped between 18/70 and 18/00 is far more disastrous than for earlier versions.

The result of this is stat swaps are more damaging, for more of the game, than in 3.1.0, and even more so compared with earlier versions.

[Magnate]

Another quirk: Nexus is severely undervalued in the current environment.
Until I've got a very good saving throw, I'm unwilling to go without nexus resistance.
Three things contribute to this:
1. Stat potions are somewhat more rare, because objects as a whole are more rare.
2. Stat gain requires more potions (not counting the move from 18/9x to 18/100.) Previously, you could get +2 in the initial stat gain then big chunks up to 18/70.
3. Stat gain after base 18 is no longer compressed. Previously you could rely on getting from 18/00 to 18/70 fairly quickly. Now it takes as long as getting from 11 to 18. Since the difference in power is also greater, getting swapped between 18/70 and 18/00 is far more disastrous than for earlier versions.

The result of this is stat swaps are more damaging, for more of the game, than in 3.1.0, and even more so compared with earlier versions.

Yep, good point well made. Nexus is stil valued at 10, per 2.9.x (i.e. more than rbase/fear/light/shards but less than sound/dark/blindness et al.). So presumably it's now worth more than rdark or rsound, and about the same as rblind?

CC

[Pete Mack]

It's worth at least as much as rBlind, certainly. But this may be a bug not a feature--I'm still hoping that stat gain won't be quite so painful by the time the beta comes out.

[PowerDiver]

Another quirk: Nexus is severely undervalued in the current environment.

It's not just the current environment. In a 309 based game, I chose dwarven armor + boots of stability over armor of resistance + boots of FA, and it wasn't for the stat bonuses. I might have had one element covered some other way, but I know I valued rNexus over rBase for a noticeable proportion of that game. A 240 point unresisted breath makes an underpowered char use ?telLevel. A nexus scramble means a new game.

[Magnate]

It's not just the current environment. In a 309 based game, I chose dwarven armor + boots of stability over armor of resistance + boots of FA, and it wasn't for the stat bonuses. I might have had one element covered some other way, but I know I valued rNexus over rBase for a noticeable proportion of that game. A 240 point unresisted breath makes an underpowered char use ?telLevel. A nexus scramble means a new game.

Hmmm. I've just added an extra term for multiple resists, so that the full rbase set is now worth quite a lot more than four individual items. I've increased the power of rnexus by 50% (from 10 to 15), so it's currently worth almost 3x as much as a single low resist - but still less than the full set. Let's play with that for a while and see. Foo of Resistance was underpriced without the extra term and should now be more sensibly priced, but it may now cost more than boots of Stability, so we'll have to investigate that ...

[PowerDiver]

Does your power algorithm keep track of the base object? E.g., wtih Bladeturner most of the power comes from the base item. The super-ego "Bladeturner" only adds a not too powerful activation, a resist or two, and maybe +15 AC to the underlying item.

[Magnate]

Does your power algorithm keep track of the base object? E.g., wtih Bladeturner most of the power comes from the base item. The super-ego "Bladeturner" only adds a not too powerful activation, a resist or two, and maybe +15 AC to the underlying item.

I'm not 100% sure what you're asking. If you are carrying Bladeturner along with "normal" PDSM then yes, the power ratings will be fairly close - but since you can only see this in the prices, and they'll both max out even the BM, you wouldn't notice unless you looked in the log file. A better example might be a Blade of Chaos (+9,+9) and a Blade of Chaos of Slay Orc (+9,+9) - those you would sell for very similar prices, with the latter fetching a tiny bit more, as you would expect.

If you are carrying Bladeturner on its own, there will be no reference made in the log to normal PDSM. Where would you be looking for one?