With the 5e shield spell and open attack rolls it's easy to figure out if the shield spell will block the hit or not by subtracting 5. If you didn't know the actual attack total the player than has to decide if to cast the shield spell or not. Is there a roll macro that will say if the attack hit (comparing playing AC to attack roll) but not reveal the attack result unless you mouseover it. I don't want to use gmroll because I can't ever show the players the result.