If a Monk was to hold two weapons with the light property (specifically in this instance two Sickles), but only attack with the primary hand, would they still be able to use a kick to perform an unarmed attack? The PHB, specifically one of the erratas, notes that:
Instead of using a weapon to make a melee weapon attack, you can use
an Unarmed Strike: A punch, kick, headbutt, or similar forceful blow
(none of which count as weapons). On a hit, an unarmed strike deals
bludgeoning damage equal to 1 + your Strength modifier. You are
proficient in Unarmed Strikes.
To me, this seems like a cut and dry case; unarmed strikes are NOT weapons, and instead of attacking with an offhand, a Monk could use their Martial Arts to perform an Unarmed Strike instead with a kick, headbutt, knee, etc., as referenced here in the PHB:
When you use the Attack action with an unarmed strike or a monk weapon
on your turn, you can make one unarmed strike as a bonus action. For
example, if you take the Attack action and attack with a quarterstaff,
you can also make an unarmed strike as a bonus action, assuming you
haven't already taken a bonus action this turn.
Likewise, when the character reached level 2 and was able to use Flurry, would they be able to opt to use Flurry INSTEAD of the offhand?
Best Answer
Yes
Holding two weapons does not in any way use your bonus action.
And you can make an unarmed strike in place of a melee weapon attack even with a weapon in each hand.
So if you use your attack action to make a melee weapon attack with your sickle, you can then use a bonus action to make an unarmed strike and, say, kick your opponent.
Note that you must of course meet the martial arts requirements for you to get the benefit of martial arts, but if you do then the rules allow this.
Flurry of Blows is also allowed by the same logic.