DMZ2112
Chaotic Looseleaf
Concentration is the last rule that I'm really struggling to master, and it's going to be worse at 6th level than at lower levels. Make sure your spellcasters understand it, as it's not the most intuitive rule in the game. I'm actually less concerned that they will abuse it than I am that they will assume they have broken their concentration when they actually have not. Concentration is pretty robust in D&D5.