Blue
Ravenous Bugblatter Beast of Traal
We playtested it and a number of the other variants like flanking at a few different levels early after it came out. We dropped it. It really lead to casters doing higher level slots because they were more efficient for the action, and running out of SP. And then either we got 5 minute adventuring days, or casters with mostly cantrips who were whiny. EVEN after seeing it happen and saying "I won't do that", it happened again and again.Dungeons & Dragons, with the optional Spell Points system in the 5th Edition Dungeon Master's Guide.
It's the best magic system that nobody has ever tried.![]()
Anyway, we also didn't feel casters were so lacking in flexibility and what they could do that they were underpowered without additional casting flexibility.