I will give you the situation this came up in, but essentially I would like to know whether moving away from a prone creature would trigger an opportunity attack or not.
If you move 20 feet to attack as a Warhorse while in druid Wild Shape, the creature needs to do a DC 14 Strength check or be knocked prone. (PHB p.311)
If the target fails and is knocked prone you can make a bounus attack with your hooves.
If you want to move away to be able to charge again on your next turn, would this normally trigger an opportunity attack?
I am not sure because the creature would have the prone condition, so guidance with this would be helpful.
Best Answer
Yes, the OA triggers, but they attack at disadvantage.
The moving away still triggers an opportunity attack ...
Opportunity Attacks
... but the Prone Condition in Appendix A shows that the OA(which requires an attack roll) has disadvantage.
Experience: I have used this situation to our party's advantage with some frequency in the past few years, as did my playing companions. I had the Shield Master feat; when the ruling changed a few years ago my DM no longer allowed me to first knock enemies down and then attack them with my sword. But I kept knocking enemies down ... because I could. We found out that me knocking the enemy down often allowed one of our other PCs to move in and attack, and risk the OA. With disadvantage on the OA it was usually a worthwhile risk.