Boss Weaknesses

Weakness Order

Mega Man 3 has 2 weakness loops

• Magnet > Hard > Top > Shadow > Spark > Magnet
• Snake > Gemini > Needle > Snake

There are 2 soft weaknesses to "cross over" between the loops (at least 2 that are relevant to the speedrun routes), along with the two robots that take extra damage from buster.

• Spark takes 2 damage from Needle
• Gemini takes 2 damage from Shadow
• Magnet and Top both take 2 damage from the Buster instead of only 1.

Weak Against Theirselves

Most bosses are weak against their own weapon. Not as dramatically as our dear friend Metal Man, but enough that almost any robot's own weapon is a viable backup in refights. (Notably, Gemini Man's refight is routed to use Gemini Laser against him)