Artifact generation: some interesting stats

[Derakon]

Oh, I still explore non-vault levels and check out what's lying around. But much of my endgame gear comes from vaults simply by virtue of their high useful-item density.

[Netbrian]

In practice, my go-to places for endgame stuff are vaults (for equipment) and dragon pits (for consumables). 50 mature dragons drop a lot of non-equipment; you're practically guaranteed to get some ?Destruction, !*Healing*, or ?MassBanish.

I love vaults too, but I'm trying to get out of the habit of mapping the level until I determine there aren't any convenient vaults around and then going to a new level. I miss the autoscummer.

[Derakon]

In practice, my go-to places for endgame stuff are vaults (for equipment) and dragon pits (for consumables). 50 mature dragons drop a lot of non-equipment; you're practically guaranteed to get some ?Destruction, !*Healing*, or ?MassBanish.

My last winner was wearing 7 items found in vaults at the end of the game. That's out of 12 equipment slots. Probably some of the other items he was wearing were dropped by vault monsters too.

[Timo Pietilä]

I'm curious about one more thing -- which non-unique monsters are most likely to drop an artifact at, say, dlevel 98?

I'm aware of all the usual caveats about summons and suchlike. I'm most interested in statistics for individual monsters, regardless of how rare they are.

Which deep monster has biggest good drop? Great Wyrm of many Colors or Greater Balrog I guess.

Archons are good source of stuff, they summon other archons, so once you have killed the unique angels and can handle angles with ease you can let angel explosion happen and get zillion good items. Individual archon doesn't have big chance of dropping an artifact, but 100 of them do.

[Derakon]

It depends.

The only settings that affect monster drops, for normals and uniques alike, are native depth, DROP_GOOD, and DROP_GREAT. The "native" level used for dropped items is max(monster level, average(monster level, dungeon level)). If the monster has DROP_GOOD, then the item automatically gets various positive enchantments (which also automatically prevents everything that isn't armor, a weapon, a dungeon spellbook, or an upper-tier piece of jewelry from being generated). If the monster has DROP_GREAT, then the item automatically is at least an ego item (or spellbook/ring of speed/etc.).

Generally you want to go as deep into the dungeon as possible, since that makes it easier to pass the good/great/artifact checks. However, artifacts (or at least randarts) can have maximum drop depths which prevent them from being generated if you go too deep. Usually those artifacts aren't very strong though, hence why their max depth is capped, so you wouldn't want them anyway.

Generally speaking, you get the best results from going as deep as possible and then killing monsters with deep native depths that drop lots of guaranteed-good items. The only advantages uniques have here are that they can have deeper native depths and they might get DROP_GREAT. But you'll be even better off from exploring deep vaults, since the items on the ground won't have their native depth diluted by that averaging I mentioned, and they often get boosts to their native depths beyond that, too.

[Netbrian]

I'm curious about one more thing -- which non-unique monsters are most likely to drop an artifact at, say, dlevel 98?

I'm aware of all the usual caveats about summons and suchlike. I'm most interested in statistics for individual monsters, regardless of how rare they are.

[takkaria]

Leaving aside the issue of vaults - it is a good thing that deep items be consistently good/great. If that leads to too much good loot, it is just better to restrict the number of drops.

If the problem is "too many artifacts", the solution is not "more Lucerne Hammers (Blessed)".

I couldn't agree more.

[Bahman Rabii]

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?

Leaving aside the issue of vaults - it is a good thing that deep items be consistently good/great. If that leads to too much good loot, it is just better to restrict the number of drops.

If the problem is "too many artifacts", the solution is not "more Lucerne Hammers (Blessed)".

[PowerWyrm]

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

Very easy:
- remove the check for stairs in do_cmd_go_down()
- add a "number of arts" variable to the cave structure, reinitialize it in cave_clear()
- each time an artifact is generated, increase this variable (make_artifact + make_artifact_special) and note it in a log file
- modify cave_generate:
* add an array [0..100] to track the number of artifacts (I don't think more than 100 artifacts can be generated on the same level)
* after each call to cave_gen(), increment the index corresponding to the value of the new "number of arts" variable
* remove the "break" to force regeneration
* break when the counter used for failed generations reaches 1000 (for example)
* write the results in a log file: for each depth, array[0] contains the number of times 0 artifacts were generated, array[1] contains the number of times 1 artifact was generated, and so on...
- with the new code, start a character and simply press ">" 100 times

[PowerWyrm]

There is a massive discrepancy with PowerWrym's stats: Vilya is the 2nd-least-common of the 12 alloc_prob==1 artifacts in your first list, and the most common in his. So either one of the two methods is bogus, or the variance is massive. Neither is a particularly helpful proposition.

Vilya has to be the most common, since it's a "special" artifact and can be easily generated from "good" templates. The others are mostly generated from "great" templates.

[Magnate]

Bladeturner's alloc_prob is 6. It is so rare largely because its base item is so rare and also because it is so deep. I saw Bladeturner 0.0017 times per trip, by far the fewest (The One Ring was more than ten times more frequent).

There is a massive discrepancy with PowerWrym's stats: Vilya is the 2nd-least-common of the 12 alloc_prob==1 artifacts in your first list, and the most common in his. So either one of the two methods is bogus, or the variance is massive. Neither is a particularly helpful proposition.

[myshkin]

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

Bladeturner's alloc_prob is 6. It is so rare largely because its base item is so rare and also because it is so deep. I saw Bladeturner 0.0017 times per trip, by far the fewest (The One Ring was more than ten times more frequent). Rarest artifacts, in order:

1. Bladeturner
2. The One Ring
3. Mediator
4. Vilya
5. Maedhros
6. Tuor
7. Belangil
8. Deathwreaker
9. Lúthien
10. Fundin Bluecloak

Galadriel and Carlammas appeared every time.

[Netbrian]

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

[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

[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).