Can you use darts as improvised "light melee weapons" to trigger Two-Weapon Fighting?

Question

Can you take the Attack action and use darts as improvised "light melee weapons" to trigger Two-Weapon Fighting for the purpose of making two thrown attacks?

My financially challenged first level wizard chooses the attack action. He declares the darts to be improvised daggers so they are "treated as such".

This declaration requires a ruling that a dart "is akin" to a dagger. This declaration; using the "as if it were that weapon" clause; changes them to "simple melee weapons" with 1d4 piercing damage, adds the "finesse", "light" and "thrown" properties, and gives a range of 20/60.

Improvised Weapons PHB p.147. "In many cases, an improvised weapon is similar to an actual weapon and can be treated as such. For example, a table leg is akin to a club. At the DM’s option, a character proficient with a weapon can use a similar object as if it were that weapon and use his or her proficiency bonus."

He holds them in each hand, this triggers a bonus action per Two-Weapon fighting. The thrown property permits me to thrown them in place of a melee attack. Negating the need for a melee attack.

Two-Weapon Fighting PHB p. 195 "When you take the Attack action and attack with a light melee weapon that you’re holding in one hand, you can use a bonus action to attack with a different light melee weapon that you’re holding in the other hand. You don’t add your ability modifier to the damage of the bonus attack, unless that modifier is negative.

If either weapon has the thrown property, you can throw the weapon, instead of making a melee attack with it.

This resolves the thematic head scratching of why I can uses daggers to make two attacks, but not darts due to its placement on a weapon table. It also saves a poor 1st level wizard a few coins.

Is this interpretation correct RAW?

Answer 1

No. Improvised melee weapons aren't melee weapons.

As per this ruling by Jeremy Crawford:

If a game feature says it works with a melee weapon, it means an actual melee weapon.

Another ruling clarifies that using a ranged weapon as an improvised melee weapon does not make it a melee weapon:

The act of throwing a melee weapon doesn't transform it into a ranged weapon. Melee and ranged are categories of weapons in the rules. Similarly, whacking someone with a longbow doesn't transform it into a melee weapon.

As the question notes, the Two-Weapon Fighting rules only trigger with melee weapons:

When you take the Attack action and attack with a light melee weapon that you’re holding in one hand [...]

Therefore, you can't use two improvised melee weapons to trigger Two-Weapon Fighting. Your DM, of course, is free to rule otherwise if it makes sense.

Answer 2

By RAW with the DM ruling that darts are similar to daggers, you can use them for two-weapon fighting

Improvised weapons can be treated as another weapon if the DM rules it is similar enough:

Often, an improvised weapon is similar to an actual weapon and can be treated as such. For example, a table leg is akin to a club. At the DM's option, a character proficient with a weapon can use a similar object as if it were that weapon and use his or her proficiency bonus.

If the improvised weapon can be treated as that weapon, then it gains the entire stat block of that weapon. That includes all properties, classifications, proficiency, and any skills or abilities.

It depends how you use the weapon

If the DM rules that when stabbing someone a dart is similar enough to a dagger, then the dart becomes a simple melee weapon dealing 1d4 piercing with the finesse, light, and thrown (20/60) properties.

However, if you do try to throw them then your DM will tell you "wait a second, I understand how you were stabbing people with them, but if you throw them then they are going to use the dart statblock"

Wait, JC said that hitting someone with a longbow doesn't make it a melee weapon!

That is correct, making a melee attack with an object doesn't make it a melee weapon.

The DM ruling that some object can be treated as if it were an existing weapon is what allows an object to become a melee weapon. A table leg that has been ruled to be similar to a club is a melee weapon. A dart that has been ruled to be similar to a dagger is a light finesse melee weapon.