How to combine stacks?

[LostTemplar]

Usefullness is a different thing, e.g. infravision becomes less usefull not by itself but compared with other things e.g. ESP, or huge stack of detection rods. Scaling means that stuff is not becoming junk by itself.

[Patashu]

Well, it's not necessarily the case that resists and vulnerabilities have to be equally meaningful at all points in the game. For example, infravision becomes less useful with telepathy, and free action less useful with 100% saving throw.

[LostTemplar]

vulnerabilities pretty much have to be proportional in order to be balanced at all points in the game.

One possible solution, I use, is to make resist values proportional to characters maximum HP, e.g. 10% of m_hp is absorbed from every (fire) attack. This have both scaling and "ignore weaklings" features, I like a lot.

[Derakon]

... but hugely disproportionate in the early game (e.g. if early fire monsters do 2d6 or so).

I guess you could get around that by ensuring that VULN_FIRE didn't appear before the mid-game.

Scatha has the advantage that damage doesn't really scale with level much in Sil.

If you do have a system where health and damage scale up at all significantly as the game progresses, then vulnerabilities pretty much have to be proportional in order to be balanced at all points in the game.

[Magnate]

Having vulnerability to fire mean that you always take an extra 10 damage from a source of fire damaging you is pretty clean, too.

... but hugely disproportionate in the early game (e.g. if early fire monsters do 2d6 or so).

I guess you could get around that by ensuring that VULN_FIRE didn't appear before the mid-game.

[Mikko Lehtinen]

I just had an idea for a different take that mirrors other mechanics in Mist quite closely.

- Monster casts an elemental attack on the player: Roll under Endurance for half damage. If you are resistant for the element (back to binary), succeed automatically.

- Player casts an elemental attack on monster: Roll under Endurance for half damage unless the monster is suspectible for the element. Resistant monsters always make their saving throw.

Endurance is a new skill (under Strength) that is also used for avoiding being crippled by some attacks, and for avoiding death under 0 HP.

[Scatha]

I've been giving this some thought, and it's very tempting, except that Mist has monster vulnerabilities. The simplest way to handle vulnerabilities is to add 50% to damage. It's nice symmetry if a monster's resistance reduces 50% from damage.

Having vulnerability to fire mean that you always take an extra 10 damage from a source of fire damaging you is pretty clean, too.

[Mikko Lehtinen]

(A) Resistances reduce damage taken by a set amount (or a die roll), and are additive.

I've been giving this some thought, and it's very tempting, except that Mist has monster vulnerabilities. The simplest way to handle vulnerabilities is to add 50% to damage. It's nice symmetry if a monster's resistance reduces 50% from damage.

For additional symmetry, I could introduce player vulnerabilities: negative resistances that add to the damage.

[Magnate]

EDIT: regarding constraints vs. optimization, I'm inclined to favor constraint-satisfaction problems, because they can be solved, unambiguously. Optimization problems require you to know your valuations for a bunch of traits and you can never really be satisfied that the tradeoffs you have made are the best tradeoffs.

Obviously some degree of optimization is valuable to keep every decision from being a no-brainer, but at the same time there's value in keeping most of the equipment puzzle "clean".

I think this is the difference between people who like puzzle games (old-style adventures etc.) and people who like wargames.

(I deliberately avoid the word 'strategy' because strategy can be both constraint-solving and optimising.)

[Derakon]

Much as I think I'd rather have binary resistances in Vanilla than stacking pval-based resistances (however they end up stacking in practice), I have to admit that a system that says "You take 10 fewer points of damage from all fire attacks" is pretty attractive from a simplicity perspective. You become outright immune to small sources of damage, but big attacks are still a concern; the effects of resistances on equipment becomes obvious (no more "but I have acid resistance so why is my armor still getting destroyed?"), and stacking applies in an obvious and intuitive way.

So whenever I get to write my own variant, I'll probably use that system.

EDIT: regarding constraints vs. optimization, I'm inclined to favor constraint-satisfaction problems, because they can be solved, unambiguously. Optimization problems require you to know your valuations for a bunch of traits and you can never really be satisfied that the tradeoffs you have made are the best tradeoffs.

Obviously some degree of optimization is valuable to keep every decision from being a no-brainer, but at the same time there's value in keeping most of the equipment puzzle "clean".

[Mikko Lehtinen]

While there is something to be said for straight addition of percentages as being easy to read for the player, I think there are two particularly natural candidate rules for stacking values of resistances:

(A) Resistances reduce damage taken by a set amount (or a die roll), and are additive.
(B) Resistances make you take only a proportion p of the damage, and these proportions are multiplied together.

Both of these work so that multiple sources of resistance are equivalent to having each take effect in turn. I believe (B) is used in FA and some other variants. (A) is probably even simpler, and attractive in a regime like that of V4 where armour subtracts from damage taken.

I'm changing the armour to reducing damage in Mist. Helmets, body armour and boots have their own armour dice that substract from damage to that location.

I'm going for a "board game feel" in Mist, or maybe "tabletop roleplaying feel", and B seems out of place in this particular game. I haven't really considered resistance dice that reduce damage before, hmm...

[Magnate]

So basically we're arguing the merits of a constraint-satisfaction problem vs an optimization problem

Yes! Another fabulous description. And I've always really loved optimisation!

[debo]

This is a brilliant description. I don't deny that the bridge-building is fun, but personally I find it even more fun to make use of what's left over (which is what happens in the additive system).

So basically we're arguing the merits of a constraint-satisfaction problem vs an optimization problem

[Magnate]

I think Timo's point can be reworded as:

The current Angband "equipment puzzle" is like trying to build a bridge with as few components as possible. You have a goal (e.g. cover all base resists, FA, and SI, then maximize everything else), and you have a collection of items, and the puzzle is to arrange your items so that they achieve the goal as "elegantly" (minimally) as possible.

This is only possible when most abilities are binary instead of additive. As soon as they become additive, you're instead left with questions like "do I value 10% more fire resistance over +2 STR?" which are much harder to answer.

So sure, switching resistances to an additive system would create more equipment questions. But you'd lose that elegance of constructing an equipment set that neatly covers everything you need with as little waste as possible. And you can't deny that doing that is fun.

This is a brilliant description. I don't deny that the bridge-building is fun, but personally I find it even more fun to make use of what's left over (which is what happens in the additive system).

[Derakon]

I think Timo's point can be reworded as:

The current Angband "equipment puzzle" is like trying to build a bridge with as few components as possible. You have a goal (e.g. cover all base resists, FA, and SI, then maximize everything else), and you have a collection of items, and the puzzle is to arrange your items so that they achieve the goal as "elegantly" (minimally) as possible.

This is only possible when most abilities are binary instead of additive. As soon as they become additive, you're instead left with questions like "do I value 10% more fire resistance over +2 STR?" which are much harder to answer.

So sure, switching resistances to an additive system would create more equipment questions. But you'd lose that elegance of constructing an equipment set that neatly covers everything you need with as little waste as possible. And you can't deny that doing that is fun.