Terrain Modifiers: an intuitive + flexible change

[Eleazar]

Disclaimer: The core of this idea was proposed a while ago, but i can't find the topic. I was against it then, but changes in the game and issues with the current system have caused me to change my mind.
Why:
In 1.0 many hybrid terrains often give unexpected defense/movment values. And it was difficult to combine terrains in a way that give intuitive results. An open field of snow slows elves down significanlty, but a snowy forest presents no obstacle. Should snowy hills be harder or easier to travel than plain snow or hills? How could additional cave terrains be created without making lots of new base terrains?

The solution in trunk is to allow terrains to be aliased to multiple base terrains and give the unit the best, worst, or average movent or defence from the two aliased basic terrains. While this was very flexable, it is complex and especially difficult to convey to the player how MV/Def was determined.

The following method allows variations of base terrains which are easily explained and understood. It also has the benefit of decreasing the number of basic terrain types.

What:
Movement and Defence values will be derived from the base terrain, occasionally modified by a terrain modifier. Terrain modifiers are obvious, concrete additions that effect the def/MV values of a terrain.

• Terrain Modifiers:
  Frozen (snow+ice)
  Forested
  Mushroomed (if kept distinct from forest)
  Underground
  (possibly) Sand

• Basic Terrains:
  Impassable (since these hexes cannot be entered their values are irrelevant)
  Unwalkable (lava, chasm)
  Mountain
  Hill
  Castle
  Village
  Flat
  Sand (maybe)
  Swamp
  Shallow Water
  Deep Water

This allows the creation of various terrain types that are with MV/Def values easily guessable by the player.
For most units the modification "frozen" would increase the MV cost by 1 or 2 and decrease the defence by 10%. Tundra would be replaced by Flat+Frozen, and behave in the same way. However Snowy Hills and Snowy Mountians would behave in a more obvous and memorable way. Ice (shallow+frozen) would behave much as you would expect: Water units have the advantage relative to land units.

With a little imagination i think it's obvious how a base terrain+a modifier could produce same/better values for nearly all current terrians and many proposed ones.


Notes:
• I think there should be a maximum defensive cap of 70% to prevent unusual combinations of terrains from making a unit virtually invincible.

• Mushroomed would only be a distinct modifier if mushrooms are to ever be used above ground.

• Forested should only be used as a modifier if terrains such as Swamp Forest or Forested Hill would be created. There is reasonably doubt weather these could be drawn is such a way that their dual nature is obvious. If not, Forested and/or Mushroomed should be basic types not modifiers.

[Darth Fool]

I like it. I am planning this weekend on tackling the multiletter terrain map problem, and while this is not exactly tied to it, I may try and add it in anyways. Of course, boucman might beat me to it.

[Tomsik]

Idea of the year!
Umm.. wait.. that's still begining of year... but idea it's brilliant anyway.

It makes things more intuitive, and fixes current odd(at least IMO) system.

[zookeeper]

I dislike the idea. Not because it wouldn't be an improvement to the current (1.0.x) system, but because the new terrain alias system (in svn) is better and already mostly implemented (only the UI parts are missing, AFAIK). It would be nice to at least try it in the next release, since the code already exists.

The new alias system, to put it short, allows terrain to define which of it's component terrains gives the defense value and which gives the movement value. So a Snow Forest would be alias of Snow and Forest, Snow defining the movement and Forest defining the defense. These can be combined in other ways too, I think, but this is the basic example.

The system proposed here would be slightly simpler than the alias system, if it had no aliases at all. However, the basic alias system would be retained (AFAIK), so there would still be bridges, fords etc. using aliases (and the current alias system is really unflexible, always picking the best of both mov and def). Also, defining of movement types would need to be done very carefully to make sure no unit can get a ridiculous defense (80% or over) in any base+modifier combination, or there would have to be a cap (added complexity in addition to being quite boring).

The new alias system would enable a lot more flexibility in defining how terrains behave. I doubt it would be any less unintuitive than the proposed system as long as the choices between best/worst of def/mov when creating terrains are done to be intuitive. Creating new terrains that behave in a unique way would, I believe, be more possible and/or easier with the alias system. All terrains would give a defense and movement value that's straight out of the unit's movement and defense tables.

Both systems need additional UI space to show the detailed terrain information.

[scott]

I think we should give the trunk method a try first.

I was unaware that values could be averaged.

[Dave]

I don't think I really like the idea of this being implemented, because it's quite different to what we have already, and it adds a new 'concept' to the game code: that of terrain modifiers. I don't think it's a bad idea per se, but I do think that what we have is already good enough.

What we could consider, though I'm not sure it's really necessary, is the idea of changing the way 'worst movement' works slightly:

Currently m = max(m1,m2). Instead we could have m = m1 + m2 - 1. (and in the case of three aliases, if we had such a thing, m = m1 + m2 + m3 - 2).

That is to say, if we had say snow hills, and a unit had 2 movement cost for each of hills and snow, they would have a total movement cost of 3.

I think the current system of making snow hills have a total movement cost of 2 in such a case is fine though. I really don't think we should make too many terrains have a movement cost of 3, since that makes it really very difficult for a unit to move far on them.

David

[Eleazar]

I don't think I really like the idea of this being implemented, because it's quite different to what we have already, and it adds a new 'concept' to the game code: that of terrain modifiers. I don't think it's a bad idea per se, but I do think that what we have is already good enough.

I noticed the verdict above, but i believe this has been evaluated more from a coder's than player's perspective, so i'll give explaining my perspective another shot.
I agree new concepts should not be lightly added. However, unnoticed a new concept has already been added. I'll call it "Terrain Blending Rules" (abreviated TBR)

There are now 3 different TBRs (average, best, & worst) which can be used to derive the Def and MV values of a hybrid hex. That makes 9 different ways 2 terrains can be blended.
In an extended chat on IRC no one could offer an example (besides bridges) of a desired effect that couldn't be achieved by the simpler terrain modifiers. (note: i'm not sure "average" has been implemented yet. However some devs consider it a neccesary TBR.)

I originally proposed this because, over a number of hours of brainstorming about TBR on ICR no one could think of a efficient way to display the how a hybrid terrain would be blended.
Terrain Modifiers would show snow hills as something like:
Hills+(Frozen)
The best suggestion for TBR was:
Hills,Snow (best Defense)
Hills,Snow (worst Move)

If Frame and I do our jobs right, it will always be visibly apparent which 2 basic terrains are being combined. If you also know the Def/MV values:
* with Terrain Mod system: that's all you need to know.
* with TBRs: you need to know which TBR is applied to MV and which to Def.
I don't believe most players will be able to intuit which TBR to will be used for a given terrain.

Is there still any question that terrain modifers would be easier for the player than using TBRs?

Sure, the TBR method won't kill Wesnoth. However if a newbie proposed something like this on "Ideas" i think a number of old timers would reply:
"It makes gameplay a little more complex without adding any fun: bad idea."

[Dobob]

How would bridges (and fords) work under this system? Would they need to become a need base terrain, good for both water and land units?

[Eleazar]

How would bridges (and fords) work under this system? Would they need to become a need base terrain, good for both water and land units?

Nobody wants to change how bridges work in 1.0.
I.E. the unit get to treat it either as "water" or as "flat" whatever is better.
This makes sense because with a bridge the unit has the choice of going over or under the bridge.

[Dave]

Is there still any question that terrain modifers would be easier for the player than using TBRs?

Yes.

I don't think we should have terrain aliasing rules nearly as complicated as you describe. Firstly, I don't think we should have this 'averaging' system. It'd be unworkable for movement, and I think unnecessary for defense.

Secondly, there is one main aliasing system that we want to make: aliases will use worst movement, but best defense. This is really a simple change from before, where we used best movement and best defense. We made the change because most cases (snow hills and snow forests in particular) didn't make much sense -- it was silly that a unit fast in hills but slow in snow could move fast over snow hills, or that a unit that was fast in snow but slow in hills could move fast over snow hills.

There are only two exceptions to this: bridges, where we want to use best movement, and best defense, and fords, where we want to use best movement, and worst defense (and we're not even sure about fords).

As you have admitted, terrain modifiers can't handle bridges (and presumably fords). To handle them properly, they will need an exception, just like the current aliasing system will.

IMHO the aliasing system where we use worst movement, best defense, is actually simpler than the modifiers system. The only cases where it is changed are cases where the modifiers system falls down too. So, I don't really see any advantage of the modifiers system over the aliases system, other than if people like the idea of e.g. culmulating defensive advantages in the case of snow/hills, which I think is of dubious gameplay value.

I do completely agree that we shouldn't throw around the possibility of making terrain use min/max/avg of defense and movement though. That would be far too complicated.

David

[Eleazar]

There's too much missunderstanding is talks about terrain.

To facilitate future discussion of i've added a wiki page of Standard definitions to Terrain Terms

[zookeeper]

I should have added that I think the possibility of averaging mov/dev in TBR is a bad thing, and much too complicated. However, I still think the possibility of choosing which component terrain gives min/max mov/def is only a good thing, when considering that none of the existing terrains needs to be changed to work in any other way than best defense + worst movement. Except bridges etc.