There is a "Scratch Feature". You could also re-organize and take off the armor.
The game allows for this, so if you don't do it, its not the software, but the player who is forcing the perpetuity.
Mario Bros. has a timer, for instance.
I think they mean that they can't do enough damage to break the block and the enemy blocks every turn. Why organize the armor and die when you can just close the tab.
