[MUD-Dev] Re: let's call it a spellcraft

[Travis Casey]

On 23 September 1998, James Wilson wrote:
> On Wed, 23 Sep 1998, Travis Casey wrote:

>>Of course, even if a character can *design* a spell, that doesn't
>>necessarily mean he/she can *cast* it.  Most spell design systems end
>>up by assigning a difficulty of some sort to the spell -- either a
>>difficulty value for difficulty-based systems, or a spell level for
>>systems which use those, or something else like that.  Thus, the
>>character may research the Apocalypse spell, and then find that he/she
>>won't be able to cast it until he/she reaches 51st level.

> most spell systems I've seen are based on the idea that a given spell
> has a certain degree of efficacy (sometimes dependent on caster level).
> I dislike this constraint and have been thinking about a system as follows:

> ('power' here means the amount of work done by the spell, e.g. the number
> of hp done in damage, the weight lifted, etc)

> 1. effects are independent from the power of such effects.
> 2. complex effects are more difficult to produce.
> 3. making a given effect more powerful consists of dumping more
> of the mage's available energies into it.

I also dislike that constraint, and have worked on similar systems.
In particular, I've worked on a system using a variant of the
Mage2Mage SDL (spell description language -- a programming language
for spells) which separates these out as you're describing.

The way it works is fairly simple:

To create a spell, the mage has to describe it using SDL.  An example
of such a spell description might be:

Fireball <power> <target>:
  create fire power <power>
  move fire to target <target>
  resize fire to 20 foot sphere
  destroy fire

(please don't take this as gospel... I'm winging this example, and
it's been a while)

The complexity of a spell is determined by simply going through the
series of commands it uses and creating a sum.  For example, you might
decide that each line of the spell (when written in a standard format
of one command/line) adds one to the complexity of the spell.

That complexity is what is used to determine whether a character can
succeed in casting the spell.

As the spell "runs", it requires power.  Specifically, certain
commands will draw power.  The power requirement may vary depending on
just what's being done -- e.g., the more powerful the fire you decide
to use in the Fireball spell, the more it costs.

> for example, producing flame is a trivial magical effect, so should be very
> easy to learn. Producing a tiny bit of flame should likewise only take a
> small amount of energy. However, a mage who knows the 'flame on' effect
> is free to dump scads of magical energy into it in order to create lots and lots
> of flame. This would, of course, be rather an inefficient way to kill people
> (most of the energy would go to heating up the atmosphere), but there's nothing
> _complicated_ about it.

Yep... that's exactly what happens.  You can use simple spells and put
lots of power behind them, and they're easy to cast... you just have
to have the power available.  More complex spells, such as spells
which have to make decisions, wards, etc., are harder to cast, but may
not require as much power depending on what they're doing.

> Advancement as a mage would then consist of learning new, more subtle
> effects and increasing one's capacity to manipulate magical energies. The
> two are quite distinct and one can easily imagine a demon, for instance,
> which wields huge amounts of energy but is not particularly skilled in its
> application.

For that matter, a standard fantasy device is an apprentice mage who
has great potential power, but isn't very skilled yet... something
this sort of system handles well, but more traditional RPG magic
systems don't.

Another side effect of this system is that power is used when the
spell does something... which may not be until much later.  For
example, if you create a ward which will fry anyone who touches it, it
uses very little power while its waiting for someone to touch it.
However, when someone touches it, it has to create whatever effects
will do the frying, which may take considerable power... and its when
the effect is created that the power is drained from the mage!

This means that a mage who leaves behind lots of wards may find
him/herself suddenly having power drained at an unexpected point.

Of course, there is a way around this... one can invest magical energy
into items, and spells can be rebound to draw their energy from those
items.  Of course, then you have to worry about recharging the item
from time to time.  Another possibility is to bind a spell to someone
else for its power source -- this could be a demon who you have
summoned and bound to maintain the spell for you, or an elemental, or
even another person!

>>Deciding the granularity of the effects is an important thing -- for a
>>paper RPG, I prefer low granularity, since the GM can work out
>>details.  In an mud, I'd prefer high granularity, so the automated
>>systems can do more of the work.

> yes, this is very important if you don't want to stick the admins with the
> job of implementing all the spells that players want to develop.

Yep.  Personally, I'd want the admins to at least review all the
spells the players create, to make sure no one's found a loophole in
the spell system, but the more automated checks that can be done, the
easier such a review should be.

--
       |\      _,,,---,,_        Travis S. Casey  <efindel at io.com>
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