Angband Forums

Angband Forums (http://angband.oook.cz/forum/index.php)
-   Vanilla (http://angband.oook.cz/forum/forumdisplay.php?f=3)
-   -   Feature branch drop balancing (http://angband.oook.cz/forum/showthread.php?t=8993)

fizzix July 8, 2018 05:04

Feature branch drop balancing
 
1 Attachment(s)
The last time we did a dedicated balancing effort with regards to drops was 3.4 I think. After that, some of the changes introduced in 4.0 broke stats generation. Over the past few days I've tracked down some of the bugs that would cause crashes after some tens of thousands of levels. (One memory leak, and two rare events), which means that we now can generate stats for the feature branch, and probably the current 4.1.x branch. I'll try to do some more detailed analysis in the coming days, but right off the bat I noticed one difference.

The standard metric I've used for general balance is to full clear every level once from 1 to 100. This, of course, doesn't really mimic how a regular player plays, but it is certainly useful for comparing across versions.

So here's what I noticed at first. 4.feature will provide you with about 59 artifacts per game (standard deviation about 2). 3.4 provides you with 51 (standard deviation also about 2). This means 3.4 is somewhat more generous with artifacts.

But, here's something that surprised me. 4.feature has, on average, far fewer monsters than 3.4. In fact at about level 40, the two branches diverge, with 4.feature having about 60% of the monsters per level than 3.4. There are a lot of possible reasons for this. But right now it's looking like 4.feature is probably being too generous with floor drops.

More analysis to come. Some things in stats are probably broken currently, (spell books for example) so I need to do some testing to make sure stuff is getting calculated correctly.

Pete Mack July 8, 2018 06:32

That explains a lot about the 3.4 game I am playing. The deeper levels feel significantly more dangerous than 4.0 (and teleportation is too dangerous to use.) Add this to 15% fewer artifacts per 100 levels, and the ridiculous rate of high end ego items in 4.0, and there is a big difference in game difficulty.

Nick July 8, 2018 13:43

Cool, I look forward to seeing more.

The lower monster rate is possibly related to changes in dungeon gen in 4.1.

fizzix July 8, 2018 15:37

3 Attachment(s)
Quote:

Originally Posted by Nick (Post 131581)
The lower monster rate is possibly related to changes in dungeon gen in 4.1.

Yup, both changes are probably related to dungeon gen. Some of this is probably a consequence of many more special rooms that are large but fairly weakly populated and have guaranteed items. The varied rooms are a general plus, but we might want to increase the monster generation rate in them.

The fact that they diverge after level 50 might be due to the former prevalence of pits/nests which used to spawn 1 or 2 per level and now spawn significantly less frequently.

As a next step I looked at stat potions, which I've used in the past as a good gauge of how generic non-artifact drops are behaving. I've split it into 3 graphs, total stat gain drops, drops from monsters, and drops from the floor (including vaults). I don't remember if Charisma was dropped in 3.4, but regardless it's not counted in the stat potion count. Augmentation counts as 5 stat potions.

There are some surprising takeaways from these figures.

The bulk of stat potions are dropped by monsters

Monsters are more likely to drop stat potions in 4.feature than 3.4, You get more potions dropped only in the later levels in 3.4 where the monster count is much higher. (I could make another plot of stat potions per monster if people want to see the actual numbers).

Not many of the stat potions are generated on the floor, yet this value is much higher in 4.feature than in 3.4, and increases very rapidly at high levels. It even increases more rapidly right at stat gain depth.

Monsters are much more likely to drop stat potions OoD (out of depth) in 4.feature. OoD drops appear to be zero until about level 20, yet you see the possibility of finding stat potions at surprisingly high probability rates in 4.feature. Rare drops should happen, but there's an indication here that we're being too generous with good early drops.

Pete Mack July 8, 2018 16:07

Can you do a plot of "high end ego items?" I am not sure how to define it, but it is basically boots of speed+big 3 weapons with big 3 enchantments+crown of might. Maybe shield of preservation and higher dragon armor Dwarven.

fizzix July 8, 2018 17:38

3 Attachment(s)
I'd have to modify the stat tracking program to get all of that. But I do track already all of Holy Avenger, defender, westernesse and gondolin. So hopefully that's good enough. I've plotted the drops of the sum of those 4 egos, and separately speed rings. (Jewelry is generated differently than weapons and unsurprisingly has different results)

Way more ego items are generated in 4.feature, both from monsters and vaults. For speed rings there's an increase in vault drops but surprisingly not much of an increase from monster drops.

Will post the ring info in the next post (can only attach 5 files at once)

fizzix July 8, 2018 17:39

3 Attachment(s)
Here's the info for the speed rings.

Pete Mack July 8, 2018 17:44

Actually, I was thinking of +attacks rather than Westernesse, which actually do have a maximum depth under DL 100. (It's a problem for artifactless mages.) But this graph is pretty much what I expected: essentially every big 3 weapon in a vault is good enough to use.

fizzix July 8, 2018 17:44

One other big difference. I also track the first time you find an item with a given ability.

In 3.4, on average you find an item with free action (could be anything including amulet of inertia) by level 22 (stdev about 2). in 4.feature that is down to level 13 (with stdev also about 2).

You have about a 42% chance to find an item with free action by level 20 in 3.4 That's up to 90% in 4.feature.

Telepathy also has a similar disparity.

in 3.4 you will on average find an item with telepathy by dungeon level 52 (stdev about 4). in 4.feature that's down to level 38 (stdev 3.5)

4.feature appears to be way more generous across the board.

fizzix July 8, 2018 17:46

I could have included extra blows weapons too (I track them). From spot checking numbers by eye they don't look any different from Westernesse or Holy avenger.


All times are GMT +1. The time now is 14:35.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.