Thoughts on the Warlock

[Max_Killjoy]

An easy way to make warlock spells scale is to just use DMG spellpoints. If a fifth level warlock has 10 SP per short rest (computed by summing up the value of his two 3rd level slots), he can cast Hex I for two spell points, switch to Invisibility for another two spell points, and still have room for a Hypnotic Pattern or else a Mirror Image + Hex. You don't waste spell points on useless upcasts.

Is there somewhere I can look this "spell points" system up, at least the basics, without a DMG?