crashtestdummy
First Post
Er...you do realise that Shield protects against all the enemy's attacks, as well as the attacks of any other foes prior to the caster's next turn, not just the enemy's primary attack? It's not just one attack as you've indicated. Protecting against the opportunity attack (assuming the bard needs to use the Dash action because the Disengage action is not viable) requires a second casting of Shield because it only lasts until the start of the caster's next turn.When you cast Shield, you are defending against the enemy's primary attack and an opportunity attack (when you run away).
As an example, if a couple of foes appear behind the party where the bard is located (such as from a secret door) and if those foes have two attacks each, Shield will protect against all four attacks, not just one. Misty Step protects against none, and Cutting Words protects against only one.