How can I cast what can't be cast?

Question

I'm running a Pathfinder campaign with the Eberron 3.5 setting, and I'm often finding that I want my players to be able to use magic in a way that the rules don't allow.

For example, a party is in an area closely linked to Fernia (the fire plane) and it is reasonable for them to find a way to pass through, without casting plane shift, but with some cost.

How can I model a cost for any spell like effect that makes it accomplishable for the lower level party, but has a similar resource requirement.

By resource requirement I mean that it should diminish the parties resources (mystical, material, whatever) by some amount roughly equivalent to casting the spell. These effects are largely plot driven, but occasionally the players will ask the inevitable "Can I do X", and I'd like to have a way to figure out the cost to them.

The ideas I had for resources that could fulfill the cost:

• Spell levels given up
• Action Points
• Hit Points
• Material Components (essentially monetary cost)

Does anyone have any experience modeling characters producing effects beyond their normal capabilities?

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It was asked how the existing spell services, scrolls, and other items don't fit my needs. Services don't make sense because I intend for this to be something the party can do. Scrolls don't make sense because these activities don't require preparation or an item in particular (Note the beginning says in a way the rules don't allow). In system terms I'm looking for something like you might find in a video game when entering an area that says "spend X here to do Y", thematic magical options for characters in a scene.

Answer 1

One possibility is to borrow mechanics from the 4th edition rituals. Basically, make a magic ritual that requires a skill roll (Knowledge: The Planes or Spellcraft might make sense) and allows the party to pass through a manifest zone to the plane it is linked to. Since a scroll of Plane Shift is 1125 gp, this ritual should probably cost much less than that, perhaps 500gp. The players would then need to learn the ritual somehow (how difficult that is depends on you), and then spend expensive components to use it. Alternately, you could look into the Incantation rules in Unearthed Arcana (page 174) and adapt those to Pathfinder.

Answer 2

With this particular scenario, I would suggest that certain spells have additional effects. Since the fire plane is your destination, maybe casting a spell with the fire descriptor in the area fails, instead "tearing" a short-lived rift in the form of a Gate to the plane. This way, some magic needs to be expended, but it can be at a much lower level.

Additionally, this allows the players to need to expend some effort in terms of discovering this interaction. Maybe some local lore tells of a wizard who long ago disappeared in the area while attempting to battle off monsters with a fireball, or maybe the interaction is well known and easily discovered. You could make the requirement slightly higher—a fire spell of at least X level—so simple pyrotechnics may not work but burning hands would.

The cost is arbitrary, based on how taxing you want the spell to be, set by the GM in accordance to the players' levels. Cost is whatever spell you choose to make the rift appear, be it in spell slots used by the party wizard, or gold spent on a scroll or wand. If you want to make the cost high, choose the highest level fire spell you know your party can cast. If you want a trivial casting cost, stick with any fire spell—including pyrotechnics—as the trigger.

Answer 3

How about this: Declare that inside manifest zones (or other areas where the environment, by its very nature, suggests that some supernatural activity should be more possible than usual), players can perform rituals to achieve supernatural effects approximately equivilent to spells. However, in order to do so, they need to spend great amounts of time incanting, waving their hands around and otherwise attuning the local supernatural energies to produce the effect they want.

Mechanically, work it like this: Assign a point value to the ritual equal to twice the gp price of a scroll of the closest appropriate spell that you can think of (in your example, it'd be Plane Shift, which I believe costs 1125 gp if scribed by a cleric). Each week that the players spend a-ritualing, let each participating player make a spellcraft check (remembering that Spellcraft is a trained-only skill), accumulating a number of points equal to the result of the check. When the party's total accumulated number of points equals or exceeds the point value of the ritual, the effect occurs.

Optionally, allow players to accellerate the process by paying for and expending ritual components (candles, chalk, brass monkeys, etc.). Each gold piece worth of ritual components grants an extra two points towards the completion of the ritual, up to a maximum of half the ritual's point value.

Obviously, this much more effort than just casting the spell - and that's why most magic-users don't bother with it. But it has the major advantages that A) It's free, unless you count labour cost and B) It's possible regardless of level, provided the local magical energies are appropriate (i.e.: the GM says it can be done).

Mechanically, this is very similar to having the players use craft and profession skills in order to earn enough cash to buy a scroll of the ritual, but it has a flavour of them pushing back the boundaries of the arcane in order to achieve otherwise impossible supernatural breakthroughs.

In situations where it would be plausible to hire an NPC spellcaster to cast the spell rather than puchasing a scroll, you may want to use the gp cost of the former, rather than the latter.

Answer 4

Perhaps they could find a magic item that does what they want or that comes with particular recharge requirements?

Answer 5

So this makes for a more fundamental mechanic change, but nowadays in most of our Pathfinder games we use FATE aspects and points. See the house rules for the Jade Regent campaign I'm playing in.

Then if you're doing that, just like in a proper FATE game you can tag scenes or areas with aspects as well. This room is tagged with "Close to Feria, the fire plane." PCs would spend a Fate point to invoke that aspect to accomplish something like what you propose, possibly with a brief negotiation of "I'll cast some other lower level conjuration spell." Or alternately, boost a fire spell or anything else that makes sense for that aspect.

Because the problem is that any other costing - gp, hp, spell levels - becomes completely arbitrary; there's no "general rule" that makes sense, you'd just come up with a specific ad hoc cost for that scenario based on what you want from a story perspective. Which is fine - if your whole point is to get them to Feria from that room, just do it. This one costs 7 spell levels and the soul of a newborn. If these are specific plot devices, then put specific effects and specific costs scaled to the situation. If you want stuff like that to happen in general (can use rather than must use from a story perspective), use aspects, would be my approach.