I think in the almost 20 years now that I have been playing D&D, I’ve not seen any PC or NPC ever use a mount in combat. It’s always been on foot. I think a main reason for this is that I’ve been playing almost exclusively 3rd Edition and Pathfinder, and one of the many, many big flaws with that system is that it’s always too much of a bother to learn a new combat subsystem for a single encounter. So it never came up, and I never used it as a GM myself.
5th Edition does most things in much simpler ways and so I gave mounted combat (and grappling) another look. And using a mount effectively turns out to be actually really easy not requiring learning anything new. It’s just that once again, the PHB does not make the effort to explain how this works and you have to go hunting for four or five different rules in different parts of the book to piece together how it’s done.
Being up on a horse or other mount doesn’t give you any practical advantage. When you park your horse next to an enemy and then keep hacking away for a couple of rounds, the horse is not doing anything for you. Where the horse comes in really handy is when you use it in the way that actual cavalry charges were historically done. You race towards the enemy, make a single strike, and then be gone before they counterattack. And then you keep doing that round after round after round.
You could theoretically try this on foot, but with a mount it becomes much more effective because you get one additional action. When you are on a mount, you get your mount’s movement, your mount’s action, and your own action all on the same turn. The mount can only dash, disenngage, or dodge and not attack itself, but this serves you just fine here.
- Direct your horse to use its movement (60 ft.) to move past the enemy you want to attack. (No action.)
- Your mount takes the disengage action so it does not provoke any opportunity attacks from any of the enemies it moves past this round.
- When your mount has moved you into range of your target, you make your attack.
- The mount continues its movement until it has moved 60 ft.
What makes this work so well is that in 5th Edition, you don’t provoke opportunities when you are being moved by another creature. And when your mount disengages, it does not provoke any opportunity attacks either. The only way enemies can get a shot at attacking you as you ride past is to ready an action to make an attack when you come into reach of their weapons. However, they will have to ready that action before you start your charge. If your movement doesn’t bring you into their reach, their action for that round is wasted.
Enemies could try to run after you and make an attack at the end of their movement. But if you are dealing with a pursuer that has a speed of 30 ft., simply make sure you end your turn at 40 ft. away from it. If it pursues, it can either dash to get next to you and not take any other action, or move its 30 ft. and take its action still 10 ft. away from you. Then in the next round you move 10 ft. towards that enemy, make an attack, and have your mount continue to a position that is again 40 ft. away from your enemy.
This all works even better when you have other allies on mounts with you. If your enemies try to pursue you, you can scatter them over a larger area, making it harder for them to work together and gain the benefits of a being in a group.
Of course you need a good amount of space to pull this off, which is probably another big reason mounted combat rarely shhows up in D&D. But it’s a nice way to give encounters a new dynamic and have to players fight in a new situation. Because everything the players can do, their enemies can also throw against them.