(this post grew out of comments I made on this post about material components over at The Lands of Ara blog)
I love the concept of spell components but
in D&D they mostly seem to be limiters on magic casting; if you
want to cast this spell, you must first invest X amount of GP in the component
cost (or quest to find the components, which seems cool but hardly ever seems to
In other words, the components don't do anything cool and all
they do is suck from the perspective of a caster.
I have actually spent a
lot of time tinkering around with different component based magic systems and I
use a lot of this in my 4e game. Components become fun when they have magical
properties in and of themselves. I like to use them like a combination of a
spell scroll/potion (the component can be consumed, either ingested or consumed
by magic in casting, to cause a certain effect) and a spell building block
(combining different components to create new effects).
I like magic to be "logical", inasmuch as that is possible, so a creature that has a magical ability usually either has some kind of organ or gland that relates to that ability and which could be harvested as a material component for a similar magical effect, or the creature feeds on a magical plant or mineral which could be found in the area which also could be used as a component for a magical effect.
This has the awesome effect of turning random encounters into explorations of how the magical ecosystem of the game works, and often results in all kinds of unexpected plot hooks emerging from play. My campaign maps are covered with marks notating where various plant or mineral components were first discovered in play (most of them emerging from improvised responses to player investigation into the source of a magical ability used against them by a creature), and many of these areas have become destinations in and of themselves for the party as they return to harvest more of the component.
I usually just
detail the primary effect/use of the component and then adjudicate on the fly
when players start combining components. It is amazing how much more engaged
with their environment players become when they realize that plants and animal
organs might very well be magical items...
Of course, 4e has abandoned
Vancian Fire and Forget style magic, so it fits much better with a component
based system of magic. But I am sure you could incorporate similar ideas into
traditional D&D style casting. The easiest way would probably be to make
components an optional part of the spell, but one that increases the potency of
the spell if used. If you actually have some red dragon scale or whatever and
use it when you are casting Fireball, maybe it does 1 more damage per die. That
way components do something cool, they don't interfere with or limit
casting, and you might actually see casters motivated to quest for specific