I don't fully understand two-handed weapons and using potions (or other items) [duplicate]

Question

I don't understand exactly what the procedure is if a character wielding a two-handed weapon decides to use a potion or similar item that requires a free hand. The fact you need an action to drink the potion is fine, but I don't fully comprehend the part about withdrawing the potion from your backpack while you don't have any free hands, per Can a character grab a potion from a pack and drink it without using their action?

• Can the character temporarily hold the weapon with one hand, grab the potion, use the action to consume it, then return to holding the weapon with two hands? The two-handed property only states you need two hands to use the weapon, not to hold it. And freeing one hand and grabbing the potion seems to be part of the "object interaction" aspect of movement.

• If the character cannot, what is the proper procedure? Does the character drop the weapon as a free action, grabs the potion as "object interaction", uses it as an action, then later has to spend an action to grab the weapon from the ground?

Answer 1

You don't need two hands to hold the weapon just two hands to wield it effectively, that is to attack.

You can take a hand off to fumble around for a potion or scribble a magic symbol in the air. Keep in mind your turn is an expression of what you can do in 6 seconds. 6 seconds is quite a bit of time.

Answer 2

From the Player's Basic Rules v0.3, page 70.

You can also interact with one object or feature of the environment for free, during either your move or your action.

The DM might require you to use an action for any of these activities when it needs special care or when it presents an unusual obstacle.

I would rule that removing an item from a worn backpack requires special care and requires an Action. If the backpack was open and on the ground at the character's feet then I'd allow retrieving an item to use the free object interaction.

The rules say nothing about how many hands an action requires, with the exception of properties of weapons (particularly versatile, two-handed, and ammunition). I would rule that opening a backpack and retrieving an item requires two-hands.

Remember that this is medieval technology - these backpacks don't have modern features like drawcords or quick-release buckles.

The character in question would have to do something like:

Turn 1: Drop sword (free), take off backpack and remove potion (Action).

Turn 2: Drink Potion (Action), pick up sword (free).

Some time later: Pick up backpack and put it on.

Note that they do not have the sword available to make opportunity attacks in between turns 1 and 2.

Now if the potion was on a belt then I'd allow a one-handed Action to drink it (like Geralt in The Witcher games).