Allowing Disengage for free

Question

I'm the DM, and I'm concerned that combat feels pretty static.

As I understand it in RAW:

• Once you've reached melee range, moving further away will provoke an opportunity attack, unless you disengage
• disengage costs an action (unless you have a feature that lets you do it for free)

[EDIT: This understanding was slightly wrong – forced movement is excluded]

This seems to mean adventurers who get within 5' of an enemy stay there until the enemy is dead, to avoid getting an opportunity attack.

This seems to make combat rather static, which I find irritating. It seems static compared to my martial arts experience (HEMA), or to say video games. (I realise 5e is a different thing to these, but it leads me to wonder if combat is unintentionally static, given the disengage action has been provided).

Some recent instances which annoyed me –

• In a recent encounter, the tank threw the halfling at a slime (it was on the ceiling, out of reach...). They succeeded appropriate rolls, and after the combat I asked where they'd want to land. They placed themselves adjacent to the slime, as they'd be hit by an opportunity attack otherwise. I left it, as I wasn't sure I wanted to set a precedent, but I felt that they should probably land further away. [NOTE – have now realised this is already exempt from AoOs] *
• A mounted character charged into combat. Despite having plenty of move left, they ended turn next to the enemy. It feels more RP that they should pass the enemy and end turn out of melee range? [NOTE – have now realised this is already exempt from AoOs] *
• A large enemy tied down most of the players; even those which were badly wounded stayed in combat, aiming to defeat the enemy before their next turn, rather than pulling out and letting the other characters handle it. It feels unnatural that if a large monster is fighting ~4 players in melee, they'd be free to get an opportunity attack if one moves out of range – particularly if that character has moved to the back/side.

I'm thinking of:

• *Allowing a free disengage if a player enters combat 'with some momentum' (e.g. mounted or otherwise moving faster than normal). Probably I'd limit this to the initial charge into combat for the mounted character. [EDIT: I'm happy that most of these scenarios are covered by the existing force motion exclusion *
• Allowing a free disengage from behind a (large+?) creature if other players are also in combat with it and thus presumably distracting it.

Does this break things? Is there anything else I should be doing to make the combat more dynamic?

Updates

Noting some updates to my understanding, both for anyone still answering, and for the benefit of anyone who finds this question in the future:

@Cubic pointed out that forced movement doesn't risk an AoO; the rules specifically give 'gravity' as an example. Most of the 'cool' moves would be covered by this, including the thrown halfling.

It seems there's different ways of playing mounted characters; I'm going to change how I play them to allow the rider and mount's movement & actions to be interspersed, so the mounted character can do a 'rideby' attack without risking an AoO. (When a controlled mount takes the Disengage action, does the rider still provoke an opportunity attack if he or she does not also Disengage?)

My thoughts about disengaging from behind large creatures which are distracted by other PCs still remain. If a dragon has 3 PCs stabbing it in the front, should it get an AoO against one behind it disengaging? (I'm using the optional facing rules – particularly for large monsters, if the players put some effort into getting behind it)

Answer 1

Disengaging and not provoking opportunity attacks is a big part of some classes, features, abilities and tactics, such as:

• Class features like Monks' Step of the Wind & Rogues' Cunning Action
• Mobile feat
• An important feature of Slow spell is to disable opportunity attack (among other reactions)
• Just plain tactics like the tank barbarian provoking the opportunity attacks, so that the cornered spell caster can slip away unharmed on their turn
• All the ways of stunning enemy before withdrawing
• All the ways, like fear or knocking target prone, to cause disadvantage on opportunity attack before withdrawing
• All the ways, like Shove or Dissonant Whispers, which move the enemy out of the melee range (possibly giving you opportunity attack when they move)
• Just circling the enemy without leaving their range to avoid provoking opportunity attack

And then there is the other side of the coin. Players like to have their opportunity attacks too. There are feats like Sentinel, Polearm Master and Warcaster, which all give benefits for doing oppurtunity attacks.

If you weaken opportunity attack, you reduce the impact of these. I strongly recommend against doing that. It is a bigger change than you think.

Instead, try to bring these mechanism into play more. You can openly discuss all the options with players, or just have the more intelligent enemies show them the hard way. The combat in 5e is more complex than it may seem at first.

Answer 2

It would make melee focused enemies significantly less dangerous

Basically, anything that only has melee attacks is already a bit on a pickle because there are strong ranged options available. One function of opportunity attacks is to not make it quite as easy to simple run away whenever such a creature does manage to get in range. This is doubly true for any creatures with special reactions such as the Marilith.

Note there is by RAW no such thing as behind, enemies aren’t statically facing any direction. There are optional facing rules you could use, but piling homebrew rules among optional ones eventually gets tricky.

It devalues classes that have easier ways to disengage

The Way of the Drunken Master Monk, Rogues in general and especially the Swashbuckler archetype have easier ways to disengage as special class features, forming a significant part of their class identity. By making it easier to disengage in general you’re somewhat devaluing those features.

Note: D&D (especially 5e) is not a medieval combat simulator

The rules are meant to be fun, and give you a tool to play out some fantasy scenes. They’re not simulationist and as such don’t aim to produce realistic results in all cases. Noting that HEMA suggests that fights should play otherwise is an interesting anecdote, but on its own not really a sign that there’s a problem you need to solve.

Note: Forced movement does not provoke opportunity attacks

Generally speaking a creature only provides opportunity attacks when they move on their own. Being dragged or thrown does not (not very realistic, but otherwise a viable strategy for grapplers would be to just drag their grappled target past enemies for a bunch of extra attacks).

Answer 3

One issue to consider is that the threat of an Opportunity Attack is one of the few methods the party's melee characters have to protect the party's more vulnerable members.

For example, the heavily armored Fighter moves up and engages three orcs. If the orcs want to go around him and bring down the lightly armored wizard, the only thing stopping them is that the first one who tries will get attacked. If we take that away, the Fighter can't really do anything to protect his allies.

Answer 4

This removes a bunch of Monk and Rogue mechanics built around being mobile, and most of the benefits of the mobile feat.

Consider instead granting something similar to the mobile feat.

The mobile feat lets you ignore AOs if you attack a creature. A restricted version of this would be to ignore AOs if you hit a creature.

This is worse than the mobile feat to a non-trivial degree, it doesn't negate the monk and rogue disengage special abilities completely, and it should provide you with more in-combat mobility.

Looking at your examples:

• In a recent encounter, the tank threw the halfling at a slime (it was on the ceiling, out of reach...). They succeeded appropriate rolls, and after the combat I asked where they'd want to land. They placed themselves adjacent to the slime, as they'd be hit by an opportunity attack otherwise. I left it, as I wasn't sure I wanted to set a precedent, but I felt that they should probably land further away.

So, here, the halfling hits the slime, and is free to land further away.

• A mounted character charged into combat. Despite having plenty of move left, they ended turn next to the enemy. It feels more RP that they should pass the enemy and end turn out of melee range?

Here, they hit the enemy, and can move on. Only if they miss are they "bogged down".

• A large enemy tied down most of the players; even those which were badly wounded stayed in combat, aiming to defeat the enemy before their next turn, rather than pulling out and letting the other characters handle it. It feels unnatural that if a large monster is fighting ~4 players in melee, they'd be free to get an opportunity attack if one moves out of range – particularly if that character has moved to the back/side.

The players next to the monster can try to hit it; if they do, they get to withdraw from melee range, letting other characters handle it. Those who do not are stuck, and have to either risk an OA or being focused by the monster.

Verisimilitude wise, swinging and connecting enough to reduce HP is a solid distraction, and could reasonably make withdrawal safe.

Game mechanics wise, attacking risks missing and getting bogged down. So disengage still has its place.

PC-defender wise, high-AC tanks can still bog down enemies. Only enemies that far outclass them will reliably hit them. And even against a dragon, a PC fighter will have soaked at least 1 attack before the dragon stomps past them at the back line.

As an extra bonus, spellcasters stuck in melee are still in bad shape.

• If they use a save spell, this doesn't trigger, so they are still stuck.

• If they use a ranged spell attack, they have disadvantage.

They have to have melee spell attacks prepared and use them and hit with it to reliably be able to both do something and withdraw from combat.

The one downside is that shocking grasp grants much of the same benefit as this rule does; the target is unable to perform reactions. So this weakens shocking grasp.