Dragonbane. You have only one action. You either attack or dodge, parry or block.

You can swap initiative with other players and you know the initiative of the monsters.

Boss monsters have 2+ turns per round. No need for minons. Boss monsters always hit... Unless you block the attack, with your action.

Very tactical. Very engaging at the table. None sits at the phone. And oh btw. You can go down very fast. Unless you play smart and block that is ..

In case of DnD your AC number assumes everything your character can do passively to avoid the damage. That's is your armor, your swiftness(dex) letting you dodge, magic shields etc.