Below is a list of Special Weapons obtained by defeating the Robot Masters in the game Mega Man 3, how Mega Man can use them to his advantage and the Robot Master/boss who is the most vulnerable to them.

Special Weapons
Name Gemini Laser
Robot MasterGemini Man
Abilities Shoots a blue beam that can ricochet off walls at a 45 degree angle.
Against Needle Man, Gemini Man (2nd Battle)
Hard Knuckle
Name Hard Knuckle
Robot MasterHard Man
Abilities When utilized, there is a short delay before the Knuckle starts moving forward. It is somewhat slow, but has great strength. Mega Man can guide the Knuckle slightly up or down once it is moving.
Against Top Man, Wily Machine No. 3
Name Magnet Missile
Robot MasterMagnet Man
Abilities Shoots a magnet-shaped missile that travels horizontally until it is parallel to an enemy, and then travels vertically toward the enemy. If it hits an enemy during its horizontal track, it will just explode without vertically tracking anything.
Against Hard Man
Name Needle Cannon
Robot MasterNeedle Man
Abilities A rapid fire weapon that fires three needles simultaneously at slightly alternate heights.
Against Snake Man, Needle Man (2nd Battle)
Name Search Snake
Robot MasterSnake Man
Abilities Releases up to three snake probes that crawl across floors and up and down walls (but not across ceilings).
Against Gemini Man, Snake Man (2nd Battle)
Shadow Blade
Name Shadow Blade
Robot MasterShadow Man
Abilities A large boomerang-like shuriken that can be shot in 5 different directions (left, right, diagonally up and right, diagonally up and left and straight up).
Against Magnet Man, Spark Man, Shadow Man (2nd Battle)
Spark Shock
Name Spark Shock
Robot MasterSpark Man
Abilities Shoots sparks which stun when hit, but paralyzes only two enemies at a time. Weapon cannot be changed while an enemy is stunned.
Against Magnet Man, Spark Man (2nd Battle)
Name Top Spin
Robot MasterTop Man
Abilities Causes Mega Man to whirl like a tornado, damaging whatever he touches while it lasts. Must be in the air to activate it.
Against Shadow Man, Top Man (2nd Battle)
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