It was my sovereign and a lone pack of umberdroths defending a city against a 300 point army. I retreated my sovereign into the city and my umberdroths held the single doorway tile.

The enemy approached to 2 titles, then stopped advancing.

My umberdroths held their ground, not leaving the entrance to the city - and the enemy never advanced to attack them. Next turn, next turn, next turn, for 20 turns neither side moves to attack the other.

Is this a bug or not? Shouldn't the battle be declared a draw if neither side moves after 20 turns. I assume that the AI did not attack because the Umberdroths would kill them with one blow. I couldn't risk moving the umberdroths from the doorway to attack, otherwise the enemy would move one of its units into the doorway and threaten my sovereign (who had 2 hp left).