Irregular Webcomic! #4903

I've been trying to write some house rules for an old school Basic/Expert Set Dungeons & Dragons game that I plan to run with my friends soon. One thing I want to do is highlight the difference between magic-user/wizard (or "arcane" in modern terminology) magic and clerical magic.

In the fiction, it's explained that arcane magic is an intellectual affair, with the casters using their intelligence to master the skill of harnessing magical energy and using it to create controlled magical effects. In contrast, clerical magic is cast by the cleric channelling and directing the spiritual power of their chosen god, through the strength of piety and prayer.

But if you look at mechanically how spells work, they both use exactly the same game rules. Both wizards and clerics "memorise" spells - wizards by studying spellbooks, clerics by concentrating their minds and praying. Both wizards and clerics have a set maximum number of spells of different power levels that they may cast each day, a number which increases slowly as they gain experience and rise in prowess. When a spell is cast, it is "erased" from the memorised set of spells and cannot be used again that day, unless the caster specifically memorised the spell more than once. (This is not your standard sort of memorisation!) And that's basically it - exactly the same mechanics used for each type of spell, with just a veneer of flavour painted on top.

But in consultation with my friends, we've decided we want the wizard spells to be less reliable - requiring a die roll to activate successfully, and with a chance of failure, and even a small chance of backfires. But you also get the chance to modify your spells or put extra energy into them for a slightly different or a bigger effect. So wizard magic is also more flexible. Wizards are using their intellect to modify how they manipulate the magical weave of the world. It's powerful but risky.

Clerical magic, on the other hand, we want to be more reliable. Less danger, but less variability. But they could also get some different flexibility by not having to select and "memorise" all their spells beforehand. They can choose what spells to cast at any time when beseeching their god to provide magical intervention. So they don't need to constantly memorise the standard set of most generally useful spells, and can bring in unusual spells to suit unusual circumstances more easily.

These fairly simple changes to the rules we hope will provide some relevant and interesting distinctions between the two different types of spellcasters, making them actually feel different in important ways.