An example of Randart generation "gone wrong"

[Warrior]

Random artifacts have always been a much discussed topic in MAngband and much has been said about their advantages as well as their disadvantages. While I certainly don't know everything about how they work I think I know enough to see a lot of potential problems with implementing random artifacts in a multiplayer environment on servers that may be running continually for years, such as mangband.org.

One of our main worries has always been that due to this being a multiplayer game that has a static "world", as in, no frequent resets, the random artifacts would eventually "flood" the game. Of course mechanisms could be created to deal with this but it still seems like a sort of basic "flaw" with the concept being applied to a multiplayer server that runs for years.

The other main concern is that individual randarts can be unbalancing, too powerful and an example can be found in the pastelog below and the following discussion on the item in angband-dev.

This particular item is the randart equivalent to Bladeturner so it is naturally not a representative for your typical randart, but imagine on a server like mangband.org, with a large number of high level people, running for years and an item of this power theoretically (as far as I understand) being generated "every half-dozen game".

***

http://pastie.org/952243

I'll quote from the channel:

<sorear> is the randart generator supposed to ever make stuff with so many properties that it overruns the screen?
<magnate> sorear: there is no check on the number of properties on a randart. The problem you're seeing is #865
<Chessa> http://dev.rephial.org/trac/ticket/865
<sorear> magnate: I am aware of the issue; however, the randart generator giving me weapons superior to Grond is dubious
<magnate> hmmkay. Then the problem is not about the length of the description!
<magnate> With the right combination of mods it is possible that a powerful artifact like Bladeturner can become an overly powerful weapon. That's one reason people like randarts.
<magnate> It is not common - only once every half-dozen games does such a weapon occur, and of course it doesn't necessarily get generated in the game.
<magnate> IMO this is an acceptable problem. To solve it would be to compromise the rest of randart generation, AFAICT.
<sorear> "become"?
<sorear> http://pastie.org/952243 <- the object in question
<magnate> Nice. Not actually more raw damage than Grond, but the triple brand and all three x5 slays is pretty special with +5 speed. If it didn't aggravate it could be considered excessive.
<magnate> Do you have the randart.log from that game? It would be interesting to see which artifact spawned it - my guess is Bladeturner or Deathwreaker.
<magnate> It would also be good to check that it wasn't too easy to find - min depth >90 and alloc_prob 1 I would hope
<sorear> yes, I do
<sorear> how do I read this file?
<sorear> magnate: note that that is a 5 blow weapon, while grond is only 3
<sorear> and the pile of high resists would be something if I hadn't found the One *even earlier*
<sorear> /Moromur turns up nothing
<magnate> Ah well, The One is never randomised, so that isn't my fault!
<magnate> Sadly the log file does not store names, so you need to know its index number
<magnate> If you have the savefile still active, you can generate the spoiler
<magnate> That will tell us the min depth and alloc_prob
<magnate> The only way to find it in the log file without knowing the number is to find the combination of slays, so you're looking for /Anm Evl Orc Trl Gia XDr XUn XDm Acd Elc Cld
<magnate> (But sadly not necessarily in that order)
<magnate> (And yes I hadn't realised Grond was limited to 3 blows)
<magnate> It isn't the best Morgoth-killer I've ever seen, but certainly one of the best overall.
* sorear restore backup save
<sorear> ^a " 2
<sorear> Beautiful.
<magnate> ?
<sorear> artifact.spo
<sorear> is
<sorear> Moromur: Level 100, Rarity 255, 22.5 lbs, 500000 AU
<magnate> Ooh, you're playing with an old version then
<magnate> And yes that's Bladeturner - you were lucky to find it with rarity 255! What level did you find it on?
<magnate> So you're playing 3.1.1?
<magnate> Given the level and rarity, it doesn't seem overly broken
<sorear> it was index 17
<sorear> oh
<sorear> I started this game on 4/10 after a svn up
<sorear> does that count as "old"
<magnate> Yup, 17 is Bladeturner.

[Emulord]

hehehe. Thats only a little better than a +2 near-perfect fury weapon. Of course if there was going to be a "randart" server, some of the egos/base items that try to take the place of artifacts would have to be removed. That way the game would probably still be of comparable difficulty, even if it gradually gets easier as the server gets more developed. In a way, this happens now, with the "heals for stat pots" economy. Also if you're missing a resist, you can generally find it in a player shop somewhere.

It might make other difficulties, namely that you might be missing crucial resists if the RNG doesn't want to generate a randart with resist confusion or something.

[schroeder]

If randarts had more restrictions on them then regular arts did, I don't think it would be too bad... Like, only you can pick up randarts that were generated for your character...

I don't support randarts, I just think that they wouldn't break game balance if they were done right.

[PowerWyrm]

Powerful randarts always aggravate... making them hard to use except as swap items in a realtime environment. I know that the randart generator has been rewritten for the latest Angband release, I don't know if the reported problem is prior or after that change... maybe now it's less likely to generate such randarts.

With my variant (using 3.1.1 V code), I currently face a huge problem with randarts, which is related to generated items being much fewer (80% less items generated) but of much better quality, leading to randarts actually flooding the game. I'll have to find a way to change this (higher rarity, higher power values, more chances to aggravate, ...)

[PowerWyrm]

Forget the last post... the new randart generator implemented in V3.1.2 has made things WORSE!
Simply look at this...

c) The Ring 'Esgalad' (+14,+13) (+3)
+3 intelligence, dexterity, speed, attack speed.
Provides immunity to acid.
Provides resistance to lightning, fire, cold, dark.
Cannot be harmed by acid, electricity, fire, cold.
Sustains strength, dexterity.
Grants telepathy. Grants the ability to see invisible things.

When activated, it attempts to magically enhance a weapon's to-dam
bonus.
Takes 1134 to 2160 turns to recharge at your current speed.
Your chance of success is 82.3%

Using that ring in combination with THAT weapon is simply BS:

a) The Mace of Disruption of Ostolwar (9d8) (+13,+11) [+5] (+2)
+2 strength, wisdom, charisma, attack speed.
+10% to searching.
Slays evil creatures, undead, giants.
*Slays* dragons, demons, undead.
Provides immunity to lightning.
Provides resistance to light, chaos.
Cannot be harmed by acid, electricity, fire, cold.
Sustains constitution, charisma.
Speeds regeneration. Grants the ability to see invisible things.


When activated, it raises your dexterity at the expense of a rando
m attribute.
Takes 1755 to 3375 turns to recharge at your current speed.
Your chance of success is 78.5%

Combat info:
10 blows/round.
This weapon benefits from one or more off-weapon brands or slays.
Average damage/hit: 176.1 vs. evil creatures, 229.6 vs. undead,
229.6 vs. giants, 229.6 vs. dragons, 336.5 vs. dragons, 336.5 vs.
demons, 336.5 vs. undead, and 122.7 vs. others.

This combination simply wipes 90% of the monsters in the game in ONE round!!!
The full story is here: http://angband.oook.cz/ladder-show.php?id=9021
A ticket has been submitted to the V bug database (#1150)... I guess I'll wait for that before implementing the new randart generator for my variant...

[Ace]

maybe a list of properties that exclude themselves would be helpful.... e.g. if a property was picked it gets less likely that another property will be picked. In the beginning the "power" is set for an artefact which could decide how many picks are left. Things that are checked first are obviously more common. Negative abilities could give "picks back"...

Though such an suggestion probably has to go to angband first ;)

cheers and see you soon!


It would be great to have more item combinations or flavors that we have talked about in other "think tank" threads.

Maybe strong artefacts (like those 90% monster killers) could degrade over time. This would be some negative property obviously and should lead to the items destruction after some time.. Of course those super-weapons should be avoided at all costs anyway.

[blaze]

Zaxx/Warrior:

I don't know if anyone cares, but in 2002 (yes, 2002) I spent some time hacking the ZAngband random artifact generator of the time until I thought it was balanced. (To do this, I changed some formulas, and generated and inspected a large number of artifacts). Somehow, this code was never released. The code might have been lost in the sands of time, but if anyone is interested I could try to find it on my old laptop from that era. At the time, I thought it seemed like a good idea.

Regards,
-Alex

[Billsey]

I think that'd be great! Even if it never makes it into the core game, it could easily drop into a variant...

[PowerWyrm]

For my variant, I simply changed the way randarts are generated: now each player gets his own set of randarts which match the actual Angband artifacts. So you won't generate 100+ randart amulets or rings anymore, just the number allowed by the artifact.txt file.

[Billsey]

What do you do when a player picks up a randart generated for someone else?

[PowerWyrm]

Nothing... It should not happen very often though, except when a player puts one of his randarts for sale. It's his choice then to give away one of a randart type he will never find again until the randart is lost by the other player.

[Avenger]

I don't really see how cherry picking extremely rare examples of randarts is a case against them.

They're not going to accumulate, because players won't be able to house them - they could sell them right away, assuming a buyer willing to pay a worthwhile price is on or comes on soon, otherwise, they're stuck carrying them. We could potentially make randarts "soulbound", but I don't like that much - good sets of gear are rare enough as it is, and finding a great mage item on a warrior or vice versa is kinda pointless when it can't be exchanged at all.

Also bear in mind that randarts will be removed from the game when deaths occur, much like current powerful egos are now. I've already bought and lost several very powerful items in only a week or two of playing.

Yes, over many years of play, consistent player who are careful and who play a lot and who get lucky with randart generation will eventually put together a pretty awesome kit - but then they'll either attempt Morgoth and win, forcing an autoretire, or die. Both outcomes will result in the removal of their randarts from the game.

I've got to go to work now, but I have more to say on the issue, which I may add later or wait for discussion to arise.

Ultimately, I very much support randarts for MAngband, and I really don't think the fact that really good ones can be generated is a case against them - in Vanilla, anyone can find Cubragol and Ringil and Bladeturner and Feanor and Deathwreaker and all other super high end arts. In MAngband, those are almost always gonna be on other players. Why shouldn't the rest of us be able to find equivalents? If anything, I'd say this is an example of Randart generation gone right. Randarts, at least for MAngband, should be added with the explicit intention of filling the void left by the fact the key artifacts will very rarely be available. The fact that the Randart generator can replicate the power levels of those artifacts while preserving their rarity is proof that it's doing that job very well.

[Warrior]

...Why shouldn't the rest of us be able to find equivalents? If anything, I'd say this is an example of Randart generation gone right. Randarts, at least for MAngband, should be added with the explicit intention of filling the void left by the fact the key artifacts will very rarely be available. The fact that the Randart generator can replicate the power levels of those artifacts while preserving their rarity is proof that it's doing that job very well.

Hi again Avenger, I guess you didn't see my reply in this thread? --> https://www.mangband.org/forum/viewtopi ... 2045#p9455

It leads to this: A whole section of the forums dedicated only to the creation artifact replacements. Your input is valueable, so have a look and let me know what you think of these items, and if you see any holes in the resistances/abilities/area they cover, suggest your own!

[Avenger]

Heh, sorry, haven't browsed forums too much since I've been back - I mostly go looking for active threads, or posting my own. I'll have a look ;)