I'm not the first person to encounter the 'Invisible weapon glitch' but I mite be the first to discover a consistent set up for it on multiple levels. This is what I've discovered so far:
WHAT THE GLITCH DOES: Effectively duplicates a melee weapon by giving the player an Invisible copy with numerous other glitched properties such as being unbreakable, undropable, unthrowable, silent, and using unarmed takedown animations.
HOW THE GLITCH IS ACTIVATED: By picking up a melee weapon at the same time as an enemy. It does not seem to be frame perfect but the window is certainly very small.
VISUAL CUE THAT IT WORKED: Both the player and enemy will perform a 'pickup animation' for the melee weapon, but only the enemy will visually obtain it.
HOW THE GLITCH IS DEACTIVATED: By picking up any new additional weapon, catching a projectile, or ending the level.
SET-UP for "THE SLUMS": (Requires the alleyway shortcut be unlocked).
Video Example: Around 0:42
Upon entering the shortcut sprint continously past the first enemy and towards the group guarding the first Jade Shrine.
The weapon being duplicated is the baseball bat sitting on the ground next to some tires at the top of a small disability/service ramp.
Ignore all enemies and sprint directly up the ramp towards the vertical line where the concrete and yellow walls meet. At the base of said ramp your enemy will begin to make a break for the weapon.
Immediately upon hitting the wall press your pick up button. Both you and the enemy should meet at the weapon at approximately the same time.
If done correctly the player will preform a 'pickup animation' but only the enemy will visually obtain the bat, and begin attacking the player.
SET-UP for 'THE CLUB'
Video Example:
Immediately upon entering 'The Club' after defeating the bouncer outside; sprint along left-hand wall through the tables and stools towards the left most enemy of the two guarding the double doors.
The weapon being duplicated is the first one avaliable in the level. The baseball bat on the right-hand counter next to the double doors that lead to the dance floor.
For correct timing Immediately upon reaching the enemies preform a "shove" to push the left most man into the doors. The enemy on the right should make a break for the weapon.
To reach the weapon at the same time as the enemy immediately 'back-step' diagonally towards the counter after the push. Then, turn and go for the bat as quick as possible.
If done correctly both you and the enemy will preform a pickup animation but only the enemy will visually obtain it.
Thank you. A solid full length 'Wude' run on Master is so absurdly difficult but you make it look so easy in your World Record.
I'd be honored if someone can make use of any of these to brake new ones. Preferably not mine though :)
Best advice I can give to anyone looking for new undiscovered set-ups is:
Look for enemies that alway seek idle melee weapons when the player enters their aggro.
Don't bother with idle projectiles like liquor bottles or bricks. Glitched weapons cannot be thrown.
Theoretically a universal set-up to activate the glitch on any level would be if someone discovered a way to predictably make an enemy seek out a player's manually dropped melee weapon.