As the player-characters advance closer to level 50, the increased percentage of power pips diminishes the usefulness of upper level spell cards from the secondary schools.
What if there was a new 0-pip spell card available after level 50 for each of the schools that would switch power pip usage from primary to secondary? It would last until the first non-zero-pip spell card was used in the combat. This card could be added to the bottom of the teachers' spell list, or as a special cross-training quest (and since it is a secondary school spell, would still take a training point).
The names of the cards could match the respective school, like "Color of Fire", "Color of Storm", etc.
As a side-note, why are power pips always yellow? Why not have them be the color of the respective school? When this new spell card was used, they would temporarily switch.
As the player-characters advance closer to level 50, the increased percentage of power pips diminishes the usefulness of upper level spell cards from the secondary schools.
What if there was a new 0-pip spell card available after level 50 for each of the schools that would switch power pip usage from primary to secondary?
It was my hope that the newer worlds would be less magic friendly, and we would see our power pip % decrease (also the damage from a spell) in those worlds <only>. The new foes might have newer, non-magical attacks, allowing us to try our old abilities in new trials. Heck, maybe magic would be so limited that we could only cast spells up to a specific pip level, forcing a higher use of blades, etc...
That is a fair point. KingsIsle may already be planning the next world with some sort of "magical dampening" to level-set on their percentage-based cap on power pips, resistance, and accuracy percentages. That might have the side-effect of player-characters leveling up but somehow feeling weaker. It might also see base percentages go past 100% in reaction to the dampening, with the clarification that there's always a minimum chance of failure in the other worlds.
Alternately, they could just start a brand new storyline starting from level 1. They could re-use the entire spell progression, rework what Wizard City and some other worlds would look like in the distant future or past (as some other forum appends have suggested), and only allow level players reaching level 50 to start a new player-character there. For this second story line they would have the option to make all the worlds more difficult with respect to the level progression, provided they would not allow player-characters cross over between the two.
Whether or not any of this would occur, it would still create more variety in the characters if upper-level secondary spells were more readily usable.