Artifact generation: some interesting stats

[PowerWyrm]

Is it raining artifacts now in the dungeon? The answer is probably yes...

Using a special "ghost" character to generate dungeon levels, I came up with the following stats:

* each depth between 50ft and 5000ft was generated 1000 times (100000 levels generated)

* 68789 artifacts were generated

* number of times the least common artifacts (alloc_prob = 1) have been generated:
- Vilya: 48
- The One Ring: 14
- Fëanor: 35
- Zarcuthra: 32
- Ringil: 28
- Durin: 26
- Eönwë: 39
- Ulmo: 32
- Aulë: 34
- Olórin: 34
- Fundin Bluecloak: 26
- Éowyn: 32

* maximum number of artifacts generated on the same level: 45 (!)

1000ft: 103 artifacts generated on 80 levels
2000ft: 423 artifacts generated on 265 levels
3000ft: 721 artifacts generated on 357 levels
4000ft: 1300 artifacts generated on 471 levels
5000ft: 2371 artifacts generated on 602 levels

Note that, starting from roughly 2000ft, all artifact-able objects are generated "good" and half are generated "great". This could explain the high number of artifacts generated below this depth. Worth considering looking at artifact generation again?

[Magnate]

Is it raining artifacts now in the dungeon? The answer is probably yes...

Using a special "ghost" character to generate dungeon levels, I came up with the following stats:

* each depth between 50ft and 5000ft was generated 1000 times (100000 levels generated)

* 68789 artifacts were generated

* number of times the least common artifacts (alloc_prob = 1) have been generated:
- Vilya: 48
- The One Ring: 14
- Fëanor: 35
- Zarcuthra: 32
- Ringil: 28
- Durin: 26
- Eönwë: 39
- Ulmo: 32
- Aulë: 34
- Olórin: 34
- Fundin Bluecloak: 26
- Éowyn: 32

* maximum number of artifacts generated on the same level: 45 (!)

1000ft: 103 artifacts generated on 80 levels
2000ft: 423 artifacts generated on 265 levels
3000ft: 721 artifacts generated on 357 levels
4000ft: 1300 artifacts generated on 471 levels
5000ft: 2371 artifacts generated on 602 levels

Note that, starting from roughly 2000ft, all artifact-able objects are generated "good" and half are generated "great". This could explain the high number of artifacts generated below this depth. Worth considering looking at artifact generation again?

Yes, this has been the devteam view for a while now. You are ahead of us on analysing your stats, but we agree that too many artifacts are generated at the moment.

[Derakon]

The level with 45 artifacts probably had a greater vault "Huge - Modified" on it, which has 126 guaranteed-great objects generated as if they were 20 levels OOD. Or some similarly high-density vault ("Bubbles" has 80 such spaces as well as 45 guaranteed-good items generated as if they were 7 levels OOD). Especially if this was a deep vault and each level in your sim was generated as if no artifacts had been created yet, that could easily get you tons of artifacts.

The last character I had was really starving for decent gear right up until he started finding vaults. They had a huge impact -- at the end of the game, 7 out of 12 of his equipment items were from the floors of vaults, and his home had another 7 such items. I'd like to see how much vaults are contributing to artifacts.

From my understanding, normally the game silently discards items that don't meet its quality bar, which is why e.g. a great wyrm with DROP_4D2 still usually only generates two or maybe three items. A similar algorithm evidently does not hold for vaults, since all spaces that are marked as having items always have those items. Does the game instead keep generating items until it gets one that passes the quality bar? That would explain why vaults now have such a massive useful-item density compared to the rest of the dungeon.

[Timo Pietilä]

...why vaults now have such a massive useful-item density compared to the rest of the dungeon.

Greater vaults have always had massive useful item density compared to rest of the dungeon. That's the purpose of the vault. In old days getting CGV was a huge boost in game. There is absolutely nothing wrong in that. Getting maybe too many vaults... that's another problem completely.

[jens]

I've always felt that the checkered vaults are too easy, since you can avoid the too dangerous monsters and still go on and pick good items. I very much prefer vault designs that are inherently more dangerous, put the best items after an open space of some sort, where several monsters can get at you at the same time. Then you have to risk death, or be creative to get the goods.

[Derakon]

A simple fix for that would be to remove every other wall in the GCV. The center section (which has a long stretch of 8's) is quite dangerous enough as it is.

[camlost]

A simple fix for that would be to remove every other wall in the GCV. The center section (which has a long stretch of 8's) is quite dangerous enough as it is.

What about reducing the value of '8' squares. Maybe only a 50% of generate great instead of 100%? Still worth looking/clearing, but a tad less Monty-haul?

Of course, there's the NPP solution, where you actually have to kill the monsters to get the loot. But a lot of people disliked that immensely, as I recall.

[Philip]

I've always felt that the checkered vaults are too easy, since you can avoid the too dangerous monsters and still go on and pick good items. I very much prefer vault designs that are inherently more dangerous, put the best items after an open space of some sort, where several monsters can get at you at the same time. Then you have to risk death, or be creative to get the goods.

@noone in particular: Mages tend to have lots of artifacts.
@jens: Mages will banish everything, see ^^^

[Derakon]

What about reducing the value of '8' squares. Maybe only a 50% of generate great instead of 100%? Still worth looking/clearing, but a tad less Monty-haul?

We had this unintentionally for quite some time -- '8' tiles had no guaranteed-great drop, and vaults were significantly more dull.

I would rather increase the danger of vaults than decrease the rewards.

EDIT: one thing that would help here is banning group monsters from vaults, or tweaking their placement therein. The problem is that group monsters block placement of other monsters. For example, the Miniature Cell vault consists solely of a small cross-shaped placement of 5 monsters guarding good items. If the game decides that the first monster it places is a group monster, then the group will expand to fill the other four tiles, and no other monsters are generated. Since group monsters are typically less dangerous for their depth, and because this reduces the variety of foes the player has to deal with, this makes the vaults much less dangerous.

The simple fix is to modify place_monster_group; insert this after the "walls and monsters block flow" section:

            /* Vault tiles block flow past the first monster */
            if (n > 0 && cave->info[my][mx] & CAVE_ICKY) continue;

Note that I haven't tested this in the slightest. It would also result in a lot of redundant no-op loops when placing monsters in vaults since the game would try to place a lot of monsters and fail; a better solution would check if the initial monster was placed in the vault in the first place and avoid adding friends if so.

[Timo Pietilä]

What about reducing the value of '8' squares. Maybe only a 50% of generate great instead of 100%? Still worth looking/clearing, but a tad less Monty-haul?

Of course, there's the NPP solution, where you actually have to kill the monsters to get the loot. But a lot of people disliked that immensely, as I recall.

The original CGV has only every other cell "8" block. The one that has been added later is bit too much, I agree. Just reduce that to original model and it's fine. Make monsters inside vault immune to banishments, and IIRC *destruction* is already changed to remove items as well as monsters (though I'd prefer vaults being immune to earthquake and destruction like town is). No more easy cleaning.

This "vaults are too lucrative" might get a bit too much boost from dev version dungeon generation. Dungeons are now small. If you get just one GV in there you multiply the size of the dungeon. Even tiny LV multiplies item generation several times over. Single DLV probably has over ten times more items than rest of the dungeon combined, even calculating non-vault monsters in that.

[Timo Pietilä]

We had this unintentionally for quite some time -- '8' tiles had no guaranteed-great drop, and vaults were significantly more dull.

I would rather increase the danger of vaults than decrease the rewards.

There was a brief time some time ago when crown GV was accidentally marked as LV which made it a (too) common. That one is open vault where monsters can get to you pretty easily. I had lots of fun luring those "too difficult to handle" -monsters out of there to get to the loot.

Risky, but serious fun. We should design more vaults like that. 8-block monsters having open route to the player, but not direct line. It works both ways, if you go close enough to be able to tele-other you are in trouble unless you are prepared to handle multiple monsters at once.

[jens]

There was a brief time some time ago when crown GV was accidentally marked as LV which made it a (too) common. That one is open vault where monsters can get to you pretty easily. I had lots of fun luring those "too difficult to handle" -monsters out of there to get to the loot.

Risky, but serious fun. We should design more vaults like that. 8-block monsters having open route to the player, but not direct line. It works both ways, if you go close enough to be able to tele-other you are in trouble unless you are prepared to handle multiple monsters at once.

Exactly! :-)

[Derakon]

The "Miniature Cell" vault actually used to be 5 '8' tiles, open to the rest of the dungeon. That was back in ZAngband, though, so it didn't feel quite so insane (by comparison with the rest of the game).

[myshkin]

* maximum number of artifacts generated on the same level: 45 (!)

1000ft: 103 artifacts generated on 80 levels
2000ft: 423 artifacts generated on 265 levels
3000ft: 721 artifacts generated on 357 levels
4000ft: 1300 artifacts generated on 471 levels
5000ft: 2371 artifacts generated on 602 levels

Note that, starting from roughly 2000ft, all artifact-able objects are generated "good" and half are generated "great". This could explain the high number of artifacts generated below this depth. Worth considering looking at artifact generation again?

Just curious...what's your algorithm for level generation, and when do you reset whether an artifact can be created again?

With the current stats code, I've run through 60000 iterations of sending a character down the dungeon, dlvl 1 through dlvl 100, and collecting all of the objects from the floor and the monster inventories. Everything resets at the end of a dungeon trip. Obviously, a real character would not be able to behave like this, and so the statistics should not be viewed as the loot one might actually see. All numbers are per trip, except where indicated. I don't have max artifacts per level, though. None of the stats includes Morgoth's special drops. I also haven't calculated any variance, and so take my significant figures with a grain of salt.

• 70.8 artifacts
• alloc_prob = 1 artifacts:
  • Vilya: 0.094
  • The One Ring: 0.018
  • Fëanor: 0.16
  • Zarcuthra: 0.16
  • Ringil: 0.17
  • Durin: 0.17
  • Eönwë: 0.16
  • Ulmo: 0.16
  • Aulë: 0.16
  • Olórin: 0.16
  • Fundin Bluecloak: 0.14
  • Éowyn: 0.16
• level stats (on that level vs. up to and including that level)
  • 1000': 0.12, 1.1
  • 2000': 0.49, 6.8
  • 3000': 1.05, 21.6
  • 4000': 1.38, 46.0
  • 5000': 2.08, 70.8

[Netbrian]

I'm just curious -- why does neither list include Bladeturner?