D&D 5E Help me write up a dice system for spells

[Stormonu]

So, I'm somewhat riffing off of 5E's expertise dice for a "module" where spells are done as a dice pool/point sort of system.

This is the basics:

0th/Cantrip Circle spells cost 0 points; they are the wizard's at-will/basic attack.
1st Circle cost 1 points
2nd Circle cost 3 points
3rd Circle cost 5 points
4th Circle cost 7 points
5th Circle cost 9 points
6th Circle cost 11 points
7th Circle cost 13 points
8th Circle cost 15 points
9th Circle cost 17 points

- You can't put more points into a spell than you have levels.
- If you're doing a damage spell, each point converts into 1d6 damage.
- If you want to affect more than one target, each point you put into a spell (seperate from the base spell cost) lets you affect +1d4 targets (+2, if you don't want to roll).
- If you want the spell to "persist", each point you spend beyond the base spell cost extends the spell's length by +1d4 rounds (+2, if you don't want to roll). How to do spells that deal damage over time? Break the damage dice over the # of rounds with a 50% bonus?

The caster gains 2d/points per level. Is this too much or too little (with buying extra targets/time, I'm pretty sure it is)? Would it be a good idea to have a low maximum and allow for dice to be refreshed after a short rest (say, 1/2 level in points/dice) and a long rest (either all or points/dice equal to level so it takes a spellcaster up to two full days of rest to be at full strength again)?

For instance, an 17th level caster would be able to do two 9th circle spells, but then he's basically done for the day having only cantrips. Assuming a 6 encounter adventure, he could cast six 6th circle spells if he wanted to do the most powerful spell available for each encounter. That's be 11d6 damage per combat (to a single target) or in older versions throwing out a Circle of Death each combat.

Conversely, a 5th level caster could throw two 3rd level spells and be done for the day or on a 6-encounter adventure would be throwing only 1st level spells for five of the encounters, and 0th circle for one of the encounters and all other times.

Likewise, a 10th level caster (or name-level caster) could throw two 5th circle spells (and two 1st circle spells) and be done. Over a 6 encounter adventure, he'd be throwing one 3rd circle spell per encounter, with an extra 1st circle spells thrown in up to two additional encounters. All other times he'd be relying on 0th circle spells.

 

[griffonwing]

One thing you can do, for starters, is figure up what a 10th level caster would be. Have him cast a Fireball as powerful as he can. Compare that to a 3/4/5e fireball. If he can end up firing more fireballs or deal more damage, you might have some tweaking.

 

[timASW]

if i were to use the dicepool type of system for magic I wouldnt use spell points. I would make it more like a caster level check to see if your able to cast the spell that round.

Looking at the dice pools now they top out at 3d10 at 10th so I would say you roll your dice pool when casting a spell and have to get over a target DC to succeed. Maybe DC 2 for cantrips and then double it each level, so

1st takes 4, 2nd takes 8, 3rd takes a total of 16 etc.

Then since they want it vancian-ish say you can attempt to cast any spell you chose to memorize as many times as you want each day. But you have to actually succeed at the dice roll to cast the spell.

You could even have some sort of critical fail method where you can actually burn out the attempted spell slot for the day.


Just off the top of my head, probably needs tweaking but thats something I would like to see if they used a wizard dice pool.

 

[eprieur]

One idea I was toying with that is not that far off from what you are proposing and was an expantion of the expertise system that something like this:

Wizards have mana points/dice. Let's say you have 4 dice, they start at D4, they increase to D6 eventually, etc, like fighter have. One main difference is that they are not at-wills, you regain them with a short or long rest, etc.

You can cast spells by expanding mana dices, lvl 0 could cost 0 dices. You can also augment the spells by spending more dices but the mecanics would be specifc to each spell, in order to keep the flavor of the spell and the general balance.

Example: The current burning hands does 1D6 damage. It would cost 0 mana points but you could read something like. Caster lvl 1+, you can spend 1 mana dice to increase the damage by that dice, basically making it a lvl 1 spell or so.

Magic missle would cost 1 mana dice (lvl 1 spell). You could read something like: For each spell level you have above 1, you can spend 1 mana dice to increase the number of target for that spell by 1. So 1 mana to cast, at level 3 I could spend 2 mana to cast to 2 targets.

Etc.

 

[Crowsion]

A while ago I came up with a method for Wizards (and psions) to cast (or manifest) their spells continuously because, to me, I thought that wizards "forgetting" their spell once cast was odd. To me it was like, you know the spell, so you well... know the spell, period.

So, i came up with a system (that i'm now modifying for D&DN) where casters must pass a casting challenge check that gets harder to cast, the more times they cast a spell.

Initially, the DC's were low so that casters can get their average number of spells per day. Cantrips, would be free of course.

The DC for a spell would be equal to 10 + the spell level. And after each cast the DC increases by 3. This may seem like a steep rise, but this is where we add the "expertise dice" mechanic. Your caster check would be equal to your casting ability modifier (like int) + the total of all the dice you roll. We are aiming at about 2 spells per day for each spell level.

This, leads to another interesting mechanic, we can now treat metamagic feats like different maneuvers, that don't take up feat slots. If you want to use a metamagic maneuver you have to spend expertise dice, effectively acting like spells occupying higher spell levels, since without the bonus from that die it would be harder to cast, so you will use metamagic on your lower level spells to avoid miscasting the spell.

Example, a level 3 wizard with a 1d6 expertise die try to cast a level 1 spell, with 16 intelligence. The DC would be 11 and with a +3 int and a +1d6, there's about a 25% chance of failure, on the second cast, the DC being 14, there would be about a 40% chance of failure.

We can add some stipulations like you can't use more than one expertise die to increase your caster check, or at level 10 you would be able to add 3d10 and cast level 1 spells to your heart's content. The others could be use to overcome concentration check or adding metamagic.

The formula for % success is 50 + 5 x (10+casting check - casting DC)