The Compendium Arcanum-series by D20pfsrd.com Publishing is a generally cool one – taking the concept of diminishing and heightened spell-effects from Arcana Evolved and adding it to PFRPG is a sound idea and one I enjoy.
Alas, the execution in the last couple of installments has been showing some serious issues regarding how the system works regarding spell-like abilities, crafting, etc., while also sporting some issues with the individual balancing. The publisher has reacted and installment #2 and #3 have been updated and improved, with some minor changes:
#2: This has made magic missile’s diminished form non-broken and cleaned up and yes, the balancing of the most significant offenders regarding balance has been taken care of. Most, but not all, mind you. The problem still remains that all of the diminished spells, as cantrip-equivalents, can be cast infinite times per day. The interaction with other components of the system hasn’t been improved either, making it remain a problematic system to plug into one’s game. Hence, I do not consider the changes made enough to provide a full revised review of the installment. You can read my original review here!
#3: The big design-guffaws I’ve mentioned have been cleaned up by the errata and the installment benefits quite a bit from that. At the same time, not all have been cleaned up -there are quite a few still remaining and, once again, the base system’s issues regarding the interaction and balance with other components of spellcasting is not addressed. Hence, my verdict will remain. You can read my original review of #3 here!