Mana Check Spellcasting (5e Variant Rule)

Mana Check Spellcasting

If you are tired of using a Vancian (DND, pathfinder, D20) or Mana-based (Rifts) spellcasting system why not try a skillcheck system instead? How it works is Instead of gaining a number of PPE points (or spell slots…) to cast your spells, you must make an Arcana check versus the DC of the spell as you attempt to cast a spell. By default, an Arcana check is just like any other skill check, just 1d20 plus your most applicable skill, which in this case is the arcana skill most of the time.

You may cast spells of any level provided you have the spell in front of you (say in a spellbook). however you can only safely cast spells equal to or less than your level. Casting spells above your level, while possible, is dangerous as you are effectively trying to harness volumes of magical energy your body, mind, and spirit are not acclimated to yet risking arcane corruption on a failure.

additionally there is no hard limit on the number of times you can cast, provided you consistently pass your skill check to cast you can keep casting spells indefinitely. Being said, one bad roll can effectively shut down all of your magic for that level and every level above it, so beware.

Spell DC

Spell DC is equal to 10 + Spell level so for example a 0-level spell (a cantrip) has a DC of 10, a 1st level spell has a DC of 11, etc.

Success and failure

Successful casting

If you succeed on your Arcana check, the spell is cast and you still have energy left over to continue casting spells of that level.

Critical success

On a natural 20 the spell cast attempt is considered a critical success, upon a critical success the spellcaster can roll a D10 or choose one of the following effects to happen.

1. Double damage
2. Double affected targets
3. Double range
4. Immediately cast a second spell of equal or lesser level as the MageCrit to effect the same target(s)
5. Restore a depleted spell level (allowing casting of that spell level again)
6. For the next minute (10 rounds) the spellcaster is rendered magically resistant to harm taking ½ damage (rounding up) from incoming attacks.
7. For the next minute you gain the ability to teleport up to 20’ as a free action every round. You cannot teleport inside of anything, only where you can see
8. For the next minute (10 rounds) you magically regenerate 4 damage every turn
9. If you die within the next minute (10 rounds) you are immediately brought back to life as if through the reincarnate spell.
10. Time seems to slow for the caster, allowing them to take an additional action this round without penalty.

Failed casting

If you fail on your arcana check however the spell “fizzles” and doesn’t work, additionally the botched attempt drains off too much energy, depleting your reserve and impeding casting spells of that level or higher until you rest and replenish your magic. That is, unless you opt to “Burnout” as described below, see below for details.

Note: you may still cast lower difficulty spells even if you deplete your high difficulty spells as they are normally less energy intensive.

Critical Failure

On a natural 1 a spell casting attempt is considered a critical failure. On a critical Failure the DM can roll a D10 or choose one of the following effects to happen.

1. The spellcaster suffers Blowback in the form of 2 x (the spell level) in the damage type of the spell cast or suffers the effects of the spell at ½ power (if non-damaging)
2. The caster is affected as through the confusion spell (as the energies of the spell get away from them and befuddle their mind) requiring a random roll, this effect only lasts through the end of their next turn.
3. The spellcaster is rent through space and blinks to a new location within 1D20’ of where they started (roll random direction and distance) if they would teleport into the same space as something else they instead teleport UNCOMFORTABLY CLOSE to it instead. This doesn’t provoke any attacks of opportunity.
4. For the next minute (10 rounds) the spellcaster is rendered magically vulnerable, taking double damage from incoming attacks
5. For the next minute (10 rounds) the spellcaster is rendered magically blind, this effect lasts until the time elapses or another creature attacks the spellcaster.
6. For the next minute the spellcaster is rendered unable to speak, when they attempt to they find themselves unable to for some reason(most often they vomit soapy bubbles) this often precludes spellcasting.
7. For the next minute (10 rounds) any object the spellcaster touches that isn’t being worn or carried by another creature bursts into flames.
8. Until the end of the spellcaster’s next turn they suffer from the Frightened condition centered around the nearest creature to them.
9. The spellcaster accidentally transmutes themselves; they will have to save VS their own spells DC or be polymorphed into a random (but survivable) animal for the spell’s duration.
10. The spellcaster accidentally transmutes the ground around themselves rendering it into some form of difficult terrain to move or fight from. Be it slippery, jagged, unsteady, etc.

Failure on spells above one’s level

If one fails their arcana check to cast a spell higher than their own level they risk not only the listed effects of failure above but also Arcane corruption, wherein the magic twists and corrupts the spellcaster, turning them into something else. The treatment of which is difficult, to put it in modern terms it is the arcane equivalent of radiation sickness. Difficult to cure, but simple enough to make a more comfortable experience.

Simple failure

A simple failure (as opposed to a critical failure) in this situation only increases the spellcaster’s corruption level by 1D4% changing that much of their body and mind. (1% being approximately the size of their hand) an effect the wizard can attempt to save themselves from with a willpower savings throw once they realize something had gone wrong. The difficulty of said throw is DC10 and success means the wizard only gains half the rolled corruption.

Critical failure

A critical failure is far more dire in this situation, something many unhinged wizards have gambled with and suffered from. In this case the wizard’s corruption level increases by 1D100% warping their body and mind by that much, which is an effect the wizard may attempt to save themselves from by making a Willpower savings throw to resist it. The difficulty of said throw is DC15 and on a success the wizard only gains half the rolled corruption.

Burnout

Burnout, also known as bloodcasting, is a process by which spellcasters can choose to sacrifice their health and take Damage equal to the casting DC of a spell to keep casting spells of a level they’ve depleted. They take this damage directly to their hitpoints, meaning it bypasses armor, temporary hit points, etc. additionally they suffer a penalty on outside sources of healing until they take a long rest. (50% reduction on outside sources of healing, magical and technological)

If a spellcaster fails a casting check and their spell “Fizzles” they may choose to suffer burnout as a reaction and have the spell work instead. The spell level is still depleted afterwards.

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