View Full Version : A simple mana-based spellcasting system

2009-12-16, 03:59 PM
This is transcribed from the link in my signature, and it weighs in at a mere 10 paragraphs without the example class. This system was originally created by Lord Blackfang on the Wizards boards in 2006. I updated it and modified it for better playability. This is meant to completely replace the Spell Points variant found in Unearthed Arcana, which is a broken piece of trash. This system is modular, which means the various recovery components can be added or removed depending on whether you're still an old fossil that believes in the 4-encounter workday or not. I play with every component listed here.

Many attempts have been made to produce a good point-based casting system, and every one of them has failed miserably, all because of the same basic design flaw: a linear - or even exponential - increase of casting cost for higher-level spells. It may seem like common sense because everybody's doing it, but in this case, everybody's wrong.

Increasing spell cost with level required casters to have absurd amounts of spell points at high levels, which in turn allows them to cast their most powerful spells way too often at the expense of lower-level spells. This can be fixed partially by charging casters for augmentation (like in the Expanded Psionics Handbook), but it requires an unreasonable amount of work and makes the system incompatible with additional material.

So what is the solution, you ask? Quite simple, really. Instead of making casting cost go up with spell level, make it go down with caster level. Yeah, that's the entire system in a nutshell.

Mana: You have a pool of this. Casting spells drains from the pool.

Strain Tolerance: This is mana by a different name. Instead of counting mana down, casters accumulate strain points, and have a limit on how many they can accumulate. This is a purely cosmetic change -- people, generally, have an easier and faster time using addition (counting strain up from 0 to an upper bound) than subtraction (counting mana down to 0 from a pool) -- this can easily be inverted with no mechanical change.

Mana/Strain Cost: This table shows us the mana or strain cost (the costs are identical) of each spell. As you can see, the cost increases slightly with spell level (duh) but decreases with caster level - this is the most important feature of the system, the concept that finally made mana-based casting a real and balanced option.

The Rules
From here on out, the rules are described in terms of strain instead of mana, due to addition being a faster mental process than subtraction. All rules that are not specified (such as the difficulty classes of spells) are the same as in the core rules.

Strain Tolerance

Your strain tolerance is equal to your primary casting stat (the actual stat, not the stat modifier). For classes that have more than one casting stat (such as the Favored Soul), your strain tolerance is equal to the stat that would normally grant you bonus spells per day. You also gain addition Strain Tolerance equal to 1/2 your level in spellcasting classes and prestige classes that add to your caster level.

Casting a Spell

When a mana-based spellcaster casts a spell, she has to channel a portion of the mana she is using through her own body. This is taxing both physically and mentally, and is the basic limiting factor that determines how many spells a mage can cast without resting. Every spell has a Strain Cost, which depends on the level of the spell and the level of the spellcaster, as shown on the tables below. At high class levels, some spells have no Strain Cost, and this is fine - a powerful spellcaster can cast basic spells all day long.

Whenever a spellcaster casts a spell, she suffers Strain equal to the spell's Strain Cost. As she casts more spells, the Strain accumulates. As long as the total Strain a spellcaster has accumulated is lower than her Strain Tolerance, a spellcaster suffers no ill effect. Continuing to cast spells once her Strain is over her Tolerance, however, is extremely taxing on a spellcaster's body and mind.

(For the people who like fatigue-based casting:)
As soon as a spellcaster's total Strain exceeds her Tolerance, she becomes fatigued (even if she is normally immune to this condition; this is fatigue of the mind, not the body). If a fatigued spellcaster wishes to cast another spell, she must first make a Fortitude save with a DC equal to (20 + the spell's level + the amount of Strain she has over her Tolerance). If the save is successful, the spellcaster casts the spell as normal. If the save is failed, the spell fizzles with no effect and the spellcaster becomes exhausted (even if she is normally immune to this condition). An exhausted spellcaster may not cast any more spells. A spellcaster ceases to be exhausted after an hour of complete rest. (Note: The DC on the fortitude save can and should be changed based on specific classes -- I'd imagine Sorcerers would have lower saves, for example.)

If the spell is cast by a class that would normally ready spells every day, the "readied spell" is not forgotten and can be cast again, as long as the spellcaster has the available Strain to do so. The advantage that mana-based Sorcerers should have over mana-based Wizards is amount of Strain available.

Recovering Strain

(For the people who like the idea of recharge magic:)
A spellcaster loses Strain equal to 1/2 her character level (but never more than her casting stat modifier) per hour if she does not cast spells, fight, run, or otherwise exert herself. A spellcaster who is fatigued due to excess Strain ceases to be fatigued as soon as her total Strain is no longer over her Tolerance. However, a spellcaster does not recover Strain while exhausted.

(For the fossils in the world who still believe in the 4-encounter work day:)
A spellcaster recovers from Strain much faster when she rests. A full 8 hours of rest completely removes all Strain.

Example: The Mage (formerly Wizard)
The Mage is what we're now calling the Wizard under this variant. They ready spells each day in the same fashion as their Wizard cousins, but cast from Strain/Mana instead. As noted under Casting a Spell, they do not lose prepared spells once they cast them -- instead, their spells are limited by their available Strain.

Strain cost table, by caster level:
{table]Level | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

So, there you have it. A simple mana-based system that gets as far away from the "give up your lower-level spells to cast a big pile of higher-level spells" issue as possible and still be a spell point system, with pluggable recovery mechanics.

Dante & Vergil
2009-12-16, 04:10 PM
Sweet, Surgo, you brought it here!! I looove this system!!:smallbiggrin:

Project Icarus
2009-12-16, 10:43 PM
This is really my favorite out of all the mana systems I've seen. I love the fatigue-based spellcasting especially, and the flavor it lends to a campaign.

2009-12-17, 05:40 AM
I'm really thinking about adding this system to my games. I'm also currently working on a fix for the druid to make wildshape not as powerful, but still as fun.

I don't know much about balance, but I assume tis balanced for the following reasons.

1: Surgo made it.
2: It's NEW and Fantangled ideas that blow our minds.

2009-12-17, 07:11 AM
Guess where I got the strain idea from? :smallbiggrin:

I took the strain as it was a way to stop mages running around flinging spells.

2009-12-17, 09:54 AM
Why didn't you just use Surgo's system instead of creating your own?

2009-12-17, 10:13 AM
Why didn't you just use Surgo's system instead of creating your own?

Because the system was created to mimic the limit to casting is "there is only so much mana in the area to be used for spells" type magic in MtG and other fiction. However, Mages would be completely overpowered without a limit, so by borrowing the strain mechanic and modifying it I was able to cap their safe casting while still letting them cast freely.

2009-12-17, 10:28 AM
Hmm. Nice point.

2009-12-17, 11:58 AM
Interesting concept. I'll keep it in mind next time I'm tweaking with my ruleset.