This is a subsystem that’s been percolating for ages, repeatedly rising and sinking in the morass in my head. Now that I’ve been putting it together for specific systems, more aspects bubble up.
Channeling
The fundamental element of this approach to working magic is the idea that casters have to channel mana to do their thing. Lots of folks have offered up mana point/magic point systems over the years though I’ve never seen one that measured the channeling instead of setting up pools of mana. I stepped away from thinking of mana as a resource that the caster accumulated and just as surrounding energy that the caster draws on, so the focus lands on how much the caster can draw and control at a time. That’s made a significant difference.
Another key step involved stepping away from channeling a set rate of mana to a random rate. This was tied in with finding a way to vary how long it should take to cast a spell, as I want to avoid a feel of magic-as-technology with set, reliable working times. I landed on rolling dice to measure the channeling as much as to provide variable timing as anything else — one has to channel so many pips of mana to cast a spell, and that can take more or less time as determined by the roll of the dice. That randomness works out diagetically as the caster having to work to summon and channel the mana and such an endeavor being a bit different each time.
Focusing on channeling, I reckon, makes how much a caster can channel an important factor. Then, just like with purely physical exertion, how much the caster can channel before fatigue throws a wrench in the gears also becomes important. Those factors become easy to measure and regulate using the dice — how much can be channeled is set by how many dice can be cast per turn, and how much can be channeled before fatigue sets in limited by how many dice per day.
I’m starting with the idea that a caster can channel only a single die at a time. The default is one per round, though that could certainly mean one per phase where casting is considered, if more than once per round. Even if more than one die can be cast during a round, a limit on the number per round makes sense, still. The limit on how many dice can be cast during a day of activity is also readily modeled by limiting how many dice the caster has capacity for. The number of dice available at any time helps limit magic work to keep it limited in play.
With that established, it becomes apparent that the exertion model also can support PCs pushing themselves to channel mana beyond their working capacity. As runners can force themselves to continue on after hitting the wall of fatigue and eventually stumble across the finish line of a race, magicians can push themselves and work magic beyond when they should. The part to work out is how much extra they can push, how long it takes, and what the price they pay will be. I can see wizards literally knocking themselves out by way of overexertion channeling mana — keep casting until they pass out.
The amount of mana required to cast a spell is arbitrary, of course, and can be set to reflect the desired feel of the game world and play therein. I first started playing around with the channeling dice using spells from AD&D, just dropping the channeling system in to replace the Vancian slots. I landed at requiring 5 points channeled per spell level to cast.
For an individual spell of 1st level, that 5 points of mana channeled means that rolling one channeling die means the spell is powered and completed one-third of the time. I played around with requiring 4 points of mana channeled, which meant half the time a single die was sufficient. That coin flip of success worked well, on the face of it.
If I use 4 pips/spell lvl, then the odds for finishing casting using one die per spell level begin at 50% and fall for every spell level thereafter. That’s not necessarily bad, it just didn’t end up feeling the best to me. Using 5 pips per spell level, made working magic decidedly more demanding, in comparison, and immediately drove me to consider how many dice the caster would have available. With the 4-pip cost, I was looking at a single channeling die per spell level the caster was expected to be able to cast in a day. With the 5-pip cost, I had to consider how adding extra channeling dice capacity would affect casting.
Adding extra dice to the channeling capacity made a major difference. With the caster having more than one die per spell level to throw at the casting, the odds improved to make the casting more reliable. Adding extra dice to the wizard’s capacity then led to being able to perhaps cast an extra spell, if the rolls go well. It adds another choice for the player to make when marshalling resources. At this point, I’m playing around using the caster’s level plus one for the number of channeling dice available.
A first-level MU in AD&D has a single spell slot. Replacing that slot with two channeling dice means that MU could potentially cast two 1st-lvl spells instead of just the one. Even with two channeling dice, however, casting the spell isn’t a given. That’s a variance that I can get behind, as it reinforces the idea that working magic is a challenging affair and doesn’t always go as expected.
That also made me consider that idea of exertion in real terms. So, the MU spent both channeling dice on casting a sleep spell and still hasn’t managed to do so. Well, that’s when pushing the effort to gain another die for channeling has to happen, so the player rolls another die to finish the casting (likely, though still not a given) and then accumulates fatigue. That fatigue affects PC activity in general and isn’t limited to just magical working, as it causes checks for capacity and the wizard could pass out, though is more likely to end up stunned and suffer penalties to all checks for a phase or two.
As mentioned earlier and should be obvious after having read about the process so far, the use of the dice determines casting times. No longer is a 1st-lvl spell finished in the same number of segments every time it’s cast. Nope. It’s finished when the mana has all been channeled, however long that takes. So, with a low roll on the first channeling die, the spell isn’t finished in that first bit of measured time. It may be finished on the next or the one after that. This also ties to the pushed effort, as pushing to add a die can be done immediately at great cost or in another bit of time following the normal rolling at lesser cost. Again, the player can choose how to use that resource and how important finishing a spell is. I like that a great deal.
Channeling dice recover with rest, much the same as hp. I reckon allowing for one die to recover after eight hours of no magic use is something to consider; playtesting can speak to how that affects play. In general, though, I expect a full night’s rest to recover the whole of the channeling capacity, though that, too, warrants playtesting.
This is the foundation of the channeling system I’m using for magic works. There are more facets to it that will appear in later posts, of course.