Unstable Mana: magic system variant.

[Fred Brackin]

Originally Posted by johndallman

That's not the issue; the problem is that you don't now how much energy you can use. Using GURPS Magic spells sensibly requires knowing how much energy you have available.

Exactly. Rolls on random tables can be budgeted for as "Time out for annoying but mostly harmless chaos" (as long as only one chaos number comes up) but inadequate energy availability makes the whole exercise futile.

Just another word about the chaos. If the chance is 1-in6 per die it's going to be extremely common and after that boring due to repetition.

In a book by Heinlein (The Moon is a Harsh Mistress) an emergent SAI was being tutored in humor and a very useful distinction between "funny once" and "funny always" merged. Magical chaos is a lot closer to "funny once". It might end up as "funny once in a while" but not as frequent as a given number coming up ona 6-sided die.