Defensive gameplay and other tactics.

By the way, I recently played on a duel server, and I was playing as Humans, although that's not important. The main thing is that my opponent, playing as the Fortress faction, sent his upgraded Lightning Elementals (I don't remember their exact name) behind my lines and cast the Berserker rune on them, which allows them to attack each nearby enemy without taking damage. As a result, he killed a lot of my units and won. That's how effectively you can use the Berserker rune!