Can I use the additional action from the Haste spell to break free of an Assassin Vine or similar things?

Question

The description of the haste spell states, in part:

Choose a willing creature that you can see within range. Until the spell ends, [...] it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

This obviously does not allow to use any other actions that you can usually use, like casting a spell, as the more specific rule for haste beats the general rule of what actions can be used. But what if some other specific effect grants an additional option to use an action on?

For example, say an Assassin Vine has restrained me using its Entangling Vines. That grants me the additional action option of breaking free from the vines:

A creature restrained by the plants can use its action to make a DC 13 Strength (Athletics) check, freeing itself on a successful check.

Can I use my additional action from haste to try to break free?

As far as I can tell, these are two specific rules contradicting each other; neither is more "specific" than the other.

Is there an official ruling on this rules interaction? If there is no official ruling on this, does anyone know how this would be ruled in AL?

Answer 1

The haste spell's action cannot be used for anything except what it lists

The section on "Actions in Combat" states (emphasis mine):

When you take your action on your turn, you can take one of the actions presented here, an action you gained from your class or a special feature, or an action that you improvise.

These are the only things you can do with actions, so we must conclude that things like breaking a grapple or escaping from the Assassin Vine are "actions gained from a special feature" (Or we could call them "improvised actions", the result will be the same).

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This means that when haste states:

[...] That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action. [...]

It is already excluding you from using your action on an improvised action or actions granted by special features which would include attempting to break a grapple or escape from the Assassin Vine.

Answer 2

As stated in the description of haste, you may only use the action given by haste to attack, dash, disengage, hide, or use an object.

The general rule is that you may use an action to break free from vines - when the assassin vine description says a creature “can use its action”, this is referring to the action generally provided to every creature on its turn:

When you take your action on your turn, you can take one of the actions presented here, an action you gained from your class or a special feature, or an action that you improvise.

Notice, the rules describe “your action”, the ability in question refers to “its action” - these are parallel, referring to the same thing. Escaping from the vines is one of the “special features” identified in this section of the rules.

The specific rule is that the action from haste has limitations on its use. Specific beats general:

Remember this: If a specific rule contradicts a general rule, the specific rule wins.