When the title says ACT, hit either A or D. You will have less than one second to act.
A stands for ATTACK, you will attack the enemy.
D stands for DEFEND, you will defend against an enemy's attack (if they attack).
The sword deals 1-6 damage.
The shield blocks 2 damage and has a 50% chance to stun the attacker for two turns.
Click the button when you are ready.