Casting Globals when 5 are up

[JimMorrison]

Originally Posted by mighty_scoop

so in summary it first choose one of the 5 globals at random and then overwrites it if you have used enogh gems, right ?

Well to clarify, base casting cost does not count towards this.

Assuming both casters were of exact level needed to cast a spell, if the first global has 50 gems above casting cost, then yours needs 51 above casting cost to overwrite it. So casting a 30 spell cheapie global with 81 gems could theoretically overwrite an expensive gem producing global with 130 gems in it. But, hit the wrong one, and you've still wasted 81 gems.