Diego outside of the Arena should have an Advanced Tutorial quest for you that may explain a little better but here's the info from our Players Guide
Players receive a PIP each turn of the duel. PIPs are represented by small white dots along the front inside arc of the sigil that the player is standing in. If the PIP is a Power PIP, it should be glowing brighter and yellow. Power PIPs count as TWO PIPS towards spells in your main school of focus. Players are eligible to receive Power PIPs after level 10. You can increase your chance of receiving Power PIPS with certain clothing and jewelry. Spells require a certain number of PIPs before they can be cast. Some spells have a PIP requirement that is represented by an X. This means that the spell will be more powerful of you have more PIPs when you cast it.
