New combat model: d20? (was: Re: Marketing Xconq)

[Lincoln Peters <sampln at sbcglobal dot net>]

On Mon, 2003-11-17 at 14:38, Elijah Meeks wrote:
> "The other is some way of providing multiple unit
> attacks and standard combat results tables based on
> odds. Like three units against one getting 3-1 odds,
> or whatever when other factors are computed, and a
> "die roll" resolves the combat all at one time. The
> current combat models do not lend themselves to doing
> this well. So maybe with the newer Xconq programmers
> on the list now, someone can think about addressing
> these things."
> 
> I consider myself saavy enough to put together an
> interesting combat model, but not so saavy as to be
> able to write it and bug-check it within Xconq itself.
>   Would it be feasible to create a Combat Model 2 that
> affords the designer more control over combat
> resolution?  You could set it up as follows:
> 
> Designer-Defined attributes for units.
> In the same way that Combat Model 1 has Attack and
> Defense for units, except the designer could define
> new attributes and assign them to units.  This way
> someone building an armored combat simulator could
> define the attributes, "Lower Hull Front Armor",
> "Upper Hull Front Armor", "Turret Armor", and so on,
> while someone who was designing a sub game could
> define, "Stealth", "ECM", "Depth" and so on.  The
> attributes themselves do nothing, except what the
> designer defines them to do in the next step:
> 
> Designer-Defined Combat Resolution.
> With the ability to define various sets of attributes,
> we could then use simple (And more accessible for
> relative non-programmers such as myself) logic to
> define how hits are determined and how damage is
> applied.  The simplest way to do this is to have a
> hardwired To-Hit system (Like Combat Model 1) and then
> have an Attribute-To-Attack-Attribute table that
> defines which attributes are used to plug into the
> system, as well as an Attribute-To-Damage table that
> does the same for damage.  With something like the
> tank model, you could introduce a
> Attribute-Chance-To-Defend table with which you could
> simulate a little more complexity.  Even better would
> be to allow the designer to punch up the algorythm
> himself, but I think I remember bringing this up and
> being told that we wanted to limit the amount of
> complex code in .g files.

It occurs to me that this somewhat resembles the d20 combat model used
by Dungeons and Dragons (3rd edition and later; earlier editions use a
very different model).  Every character (or unit) has a base Armor Class
and Attack bonus.  For one unit to hit another, the attacker rolls a
20-sided die, adds the Attack bonus, and if the resulting number equals
or exceeds the defender's Armor Class, the attack hits and does damage. 
These may be hard-coded (e.g. Armor Class 10, Attack bonus +1), but
there are countless things that could alter them.  For example, a suit
of chain mail armor improves Armor Class by 5 points (reducing the
chance of being hit by roughly 25%), a masterwork longsword would
improve the Attack bonus by 1 (hit chance increases by about 5%), and
the Two-weapon Fighting feat(s) can potentially double the character's
number of attacks per round.

Would this fit what you're describing?  In the case of tanks and/or
subs, the attributes you describe might work out as follows:

Lower Hull Front Armor:	+2 Armor Class
Upper Hull Front Armor:	+6 Armor Class
Turret Armor:		+1 Armor Class
Stealth:		+4 Attack vs. non-"Stealth" units
Depth:			+4 Armor Class vs. non-"Depth" units

Some other possible combat rules (that would require far more than just
a new combat model) might be:

Lower Hull Front Armor:	Damage reduction 4 vs. infantry
			(i.e. any damage inflicted by infantry is instantly reduced by 4, minimum 0)
Upper Hull Front Armor:	Additional +4 Armor Class to cockpit*
Turret Armor:		Additional +6 Armor Class vs. "Disarm" attacks
Stealth:		A successful surprise attack inflicts double damage.
ECM:			A successful attack imposes -2 on the defender's Attack
Depth:			+4 to avoid being detected (Hide and Move Silently checks)

* Armor class bonuses to specific parts of the unit only come into play
when an opponent makes a called shot to that part of the unit (e.g a
called shot to the cockpit would be a difficult shot (-8 to Arrack), but
it would instantly kill the unit if successful).

I've looked at the licensing agreement for the d20 system (used by D&D
3rd edition and later, as well as a few other RPG's), and it looks like
we could incorporate it into Xconq as a third combat model if we wanted
to.  However, I am not a lawyer, and the language used in the licenses
is rather weird (although not much more so than Microsoft license
agreements).  The URL's for the license agreements are:

Open Gaming License: http://www.wizards.com/d20/files/OGLv1.0a.rtf
d20 System License: http://www.wizards.com/d20/files/d20licensev5.rtf