How can a character escape after being engulfed by a shambling mound?

Question

A shambling mound will be attacking the party I DM for during tonight's session, and I am unsure about how to deal with the monster's Engulf feature.

The shambling mound's multiattack action states (MM p. 270):

The shambling mound makes two slam attacks. If both attacks hit a Medium or smaller target, the target is grappled (escape DC 14), and the shambling mound uses its Engulf on it.

So if both slam attacks hit the target, the target is grappled, and then the shambling mound immediately engulfs it. As I understand it, this all happens on the same turn, since it is part of the multiattack action.

The Engulf action states:

The shambling mound engulfs a Medium or smaller creature grappled by it. The engulfed target is blinded, restrained, and unable to breathe…

How would the target escape once it is engulfed? The DC of 14 in the multiattack description is for escaping the grapple, does it also apply to escaping after being engulfed? Or would a contest make more sense (shambling mound's strength vs. target's strength/dexterity)?

Further complicating the matter is the fact that the target is blinded (automatically fails all ability checks relying on sight). Would being blinded impact the target's ability to escape, e.g. would the target be so disoriented that it would not know which way is up or down without sight?

Answer 1

Every version of DnD sacrifices simulation for simplicity. Escaping a Grapple usually lookes like this (Monster Manual 11):

A creature grappled by the monster can use its action to try to escape. To do so, it must succeed on a Strength (Athletics) or Dexterity (Acrobatics) check against the escape DC in the monster's stat block.

Neither the Blinded nor the Restrained condition modifies this in any way. Engulf is only works on grappled targets, and no other way is listed to end it.
So you escape this grapple as you would any other, and when it ends, all the other conditions end with it.

Answer 2

The rules aren't explicit...

There are two ways of looking at this, and I'll detail both for you.

You escape the grapple, which Engulf is tied to

Since the grapple condition appears to not happen without Engulf following instantly after, it appears that the two are linked. The lack of escape DC for the Engluf feature would suggest that you are meant to escape the grapple, which would then end the Engulf feature, which is why the grapple has a listed escape DC but the Engulf does not. There is also flavor text in the MM that suggests creatures can "escape" the shambling mound, but this could go either way.

or...

The Engulf cannot be escaped

Because the Engulf lacks an escape DC, you can infer that perhaps it cannot be escaped. This makes the Engulf feature pretty good. However, if we're looking at the challenge rating of 5 compared with the "Quick Monster Stats" table on page 274 of the DMG, we can see that the shambling mound has appropriate AC, Hit Points, and to-hit modifiers, but it's damage per round is far below the suggested range of 33-38. On average, you're looking at 21 damage if it hits you twice and you fail your constitution save. This might suggest that being able to somewhat control a player makes up for the low damage and the lack of escape mechanism is built into the CR. The likelihood of both attacks hitting is low depending on who is being hit.

I think the most likely scenario is that Engulf cannot be escaped, given the balance and wording of the ability.

Is that a big deal?

Actually not really! Being restrained, grappled, and blinded doesn't affect your ability to make an attack roll and some spells don't require you to see the target. You can still be a relatively effective combatant if the combat scenario is balanced properly. Spells like Fireball, Thunderclap, etc are useful here because they require no attack and no sight. Also, hopefully you have friends nearby!

Does blinded affect the ability to escape?

That's entirely up to your DM, though personally I would say no. The rules are pretty explicit on what you need to be able to see, and grappling and escaping grapples are not something that explicitly require sight. You don't even need to be able to see to make attack rolls, it just makes it harder.

Answer 3

There are multiple factors.

The Escape DC for the grapple is 14. If both slam attacks hit, then a grapple is guaranteed and is followed up with an engulf. There are three things that happen with engulf: the target is blinded, restrained, and can't breathe.

The grapple can be escaped on the grappled character's turn provided they pass the make a 14 or higher on their check. This is all that is required by making either a STR(athletics), or DEX(acrobatics), check.

Since these do not rely on sight, then they do not get affected by the Blinded condition. Checks that rely on sight could be perception and maybe survival.

The part about not being able to breathe becomes dangerous after the length of time a character can hold their breath passes, which is 30 seconds or 1 + the characters CON modifier minutes, whichever is higher. This means that they can hold their breath for at least 30 seconds. (5 rounds)

Suffocating(Basic Rules; p. 65)

A creature can hold its breath for a number of minutes equal to 1 + its Constitution modifier (minimum of 30 seconds). When a creature runs out of breath, it can survive for a number of rounds equal to its Constitution modifier (minimum 1 round). At the start of its next turn, it drops to 0 hit points and is dying, and it can’t regain hit points or be stabilized until it can breathe again. For example, a creature with a Constitution of 14 can hold its breath for 3 minutes. If it starts suffocating, it has 2 rounds to reach air before it drops to 0 hit points.

This is my interpretation; the books are just guideline and don't need to be followed exactly as written if a given table wants to vary the effects.