The pip usage system doesn't work right. It’s not too out of sorts to be honest, but it’s not correct. If you cast a 1 pip spell, and have only a single power pip, you lose the whole pip. If power pips count as 2 pips to your primary school, then what is happening to the other half of it when you cast an odd pipped spell using an even number of pips (if they're all power pips)?
What I'm talking about (some examples): 1) a wizard casting a 1 pip spell with only a single powerpip showing. The powerpip is used leaving nothing behind. The spell just cost 2 pips 2) Any wizard casting a 7 pip spell when having 4 powerpips. It uses all 8 pips.
What I'm NOT talking about: A non-life school wizard casting pixie and it costing 2 power pips.
The game has always been that way. Regardless of how many Power Pips you have, if you use a spell with an odd number of pips required, you will always lose 1 pip if you do not have any single pips in the rack.