I started a new game to try playing through the early game a different way. (Note: My strategy is definitely not optimal)
I have on multiple occasions in this game where I have encountered fights that never end. That is, all of my living creatures are out of mana and don’t have high enough attack to damage the enemy creature. The enemy creature does not have high enough attack to damage any of my living creatures. (The first time the enemy was an a Planetary Aramanth – which has naturally high defense. The next time it happened I assume the enemy Banshee was getting significant defense from its artifact.)
This results in “0” damage attacks over and over forever.
I periodically get messages saying things like “All the creatures on the Battlefield will take 240% More Damage because they are getting tired”
However, these messages don’t seem to have any effect in my situation. (Perhaps they are just multiplying the zero damage by larger and larger values?)