Two dudes kill a troll using magic and no one is using Reagents? WHAT?

regardless of how it is handled - one thing should always be kept in mind - a mages power is in preparation, NOT in kneejerk reactions. in RPG's and Fantasy novels alike, the best stories all revolved around preparation as the key to that power. for example: the dresden files - the best parts i've experienced in that storyline was then Harry was making the potions in the sports bottles, and how that subplot unfolded throughout the stories. he never knew exactly what he needed, but he charged a potion nonetheless, and it always worked well for him. or in the Nightrunner series by lynn flewelling, those in the mage school, like Theron always prepared cantrips and charged them in innocuous items for the non-magical types. like the time Theron had a twig or something imbued with the spell that turned Alec into a stag, so he could retreat faster through the woods. All Alec had to do was snap the twig.

That being said, the preparation should, in my mind, make the prepared spell(s) much more potent, and/or last longer, and/or require fewer reagents at the time of casting.

i still believe that reagents for first tier spells/skills shouldn't be required, but would greatly benefit the user if utilized. having the ability to segue into the use of reagents that way will make the transition much more fluid, and just make the game systems feel more interconnected and dynamic.

 

I really like the idea of making essences / reagent bags, this kind of preparation might increase the cost-effectiveness of the reagent considerably, so that one would get much more "oomph" from say 50 garlic by preparing them (or buying them prepared). In emergencies one could make do with freshly picked reagents, though using them unrefined would be a lot more wasteful. Player skill level could also influence how much reagent is needed (with increased skill a reagent may be used more judiciously).

I interpret focus to be just attention energy -- every action requiring conscious effort drains focus, be it driving a car, jumping, or manipulating magical energies. Therefore I see no problem with the idea of some low-level spells requiring just focus (in addition to the required skills of course) and some (especially higher level but this need not be so straightforward) spells having mandatory reagents. Also for this reason the idea of making the spell require less focus by using reagents feels to me, well, not immersion breaking but slightly unreal(*). IMO (base) focus requirement should only be affected by 1) skill level (as a real life example, driving a car requires almost all of your focus when just learning how to drive it, and almost no focus at all from a seasoned driver) and 2) natural inclination (for example jumping is, or should be, easier if one has more dexterity, thereby requiring less focus).

(*)This is not to say that there couldn't be some psychoactive substances in the game that would modify focus requirements (actually that would sound like a lot of fun), but there would probably be consequences from using them (for example in the case of spells, increased chance of fizzling or even backfiring), and IMO they should definitely not be core reagents of specific spells.