Is dropping an Object "free" in terms of action cost?

Question

An Object is defined in the rules

a nonliving, distinct thing...

There is some debate about the action cost of dropping a Weapon; however, the set of Objects in general is larger than, and contains the subset of objects that are Weapons.

There are a number of overlapping complications to consider, since Improvised Weapons can be either objects or weapons at different times, in different contexts

An improvised weapon is an object wielded as a makeshift weapon...

And, it would be both odd and counterintuitive, to put special restrictions on weapons, as opposed to Objects unless there was an exception to the general rules.

So, the general question then is, is it free to drop an Object in general, e.g. a spellbook?

Answer 1

The rules aren't explicit

What this really boils down to, is what it means to interact with an object. The rules for object interactions never define an interaction apart from giving two examples:

(...) such as moving a lever or opening a door (...)

If we look to the dictionary definition for interact, Merriam-Webster defines it as

to act upon one another

So in the strictest of senses, the object would have to act upon the character as well for there to be an interaction. If a character simply drops an object, the object does not act upon the character and there is no interaction.

However, I think that going so deep and looking at the strict literal definition of the words in the text is missing the mark. I believe that the rules never try to specify what constitutes an object interaction on purpose. The 2014 rules had a rather extensive list of examples for object interactions, but that was dropped for the 2024 rules. I believe that was intentional to shift the responsibility over to the DM. It is also my personal opinion that dropping an object requires virtually nothing of a character and would therefore not count as an object interaction in terms of action economy.

Answer 2

Unequipping a weapon is the only edge case

The Attack action contains the only written rules concerning dropping anything.

Unequipping a weapon includes sheathing, stowing, or dropping it.

But, it never defines that act as having any cost.