What are the restrictions of an unarmed strike?
What are the global restrictions of making an unarmed strike? As it is considered a weapon, I suppose one must have a "hand free" to "punch". However, there are some gray areas I can't find any answers to.
For example, the Monk class allows a player to add an additional unarmed strike to his Attack action, as a bonus action. If one is using a Versatile weapon, can he attack using both hands, making the damage 1d8 and still make use of his additional unarmed strike(s)?
Additional remark: The extra unarmed strike granted by Flurry of Blows has no restrictions regarding the weapon(s) held. Am I missing any implied restrictions here? Or is a Monk somehow able to hold a two-handed weapon and still make use of Flurry of Blows ? If that is the case, I am to believe the unarmed strike from FoB would not be considered as weapons. Would that also mean that if a monk is wielding a quarterstaff with two hands, he could open with an attack of [1d8 + Dex] damage, followed by an unarmed strike of [1d6 + Dex] damage with a bonus action (using Martials Arts) ?
The monk's Martial Arts feature reads:
When you use the Attack action with an unarmed strike or monk weapon on your turn, you can make one unarmed strike as a bonus action.
Instead of using a weapon to make a melee weapon attack, you can use an unarmed strike: a punch, kick, head butt, or similar forceful blow (none of which count as weapons.
That, to me, makes it sound like you could attack with a monk weapon using two hands, then make a kick or head butt (or another forceful blow with a part of the body that isn't your hand) as your bonus action.