As with all Megaman games, each Robot Master can take a certain number of hits from each weapon. Some are impervious to other weapons (bullet, missile, Atomic Fire). In the fifth Skull Castle stage (or throughout the game), learn what weapons do the best damage to a specific Boss.

Metalman can be defeated with one hit from his own Metal Blades (which only use half of an energy unit each). Metalman is also easily defeated by about six to fourteen Quick Boomerangs.

Crashman can be defeated by running in an infinity symbol pattern (an elongated sideways figure 8) and shooting him with either an Arm Cannon or Quick Boomerang shot fourteen times or the Air Shooter twice.

Airman can only take two to three Leaf Shields into his intake valves. Wait until he fires his salvo of 3 Air Shooter attacks. He then jumps to the other side of the room to continue his assault. Hit him from behind. His tornadoes are bulletproof.

Flashman can be fooled into walking into a Crash Bomb placed into the left wall. Wait on the upside the until he reaches you. Place the bomb when he is two thirds of the way there. If he reaches you, stay there. Even with the Time Stopper on, the damage you do to him will more than make up for what he does to you. If it works on time, it will only take one Bomb. Otherwise, It may take two or three attempts.

If you make a direct hit with Crash Bombs on Woodman's orbiting Leaf Shield, you will take him out faster than you would with the Metal Blades. One to two hits on the shield itself will defeat him. If you hit him through the leaves, it will take more hits and weapon energy. If you use Metal Blades, it will take more than two weapon units worth to blast an unshielded Wood Man.

If you do not mind being birthday cake pink, Quick Boomerangs will easily take out Metal Man and Bubbleman. Bubbleman can also be taken out by Metal Blades as he descends from his swim.

Heatman (the giant yellow flip-top lighter) can be cooled off with the Air Shooter, Arm Cannon (P), or Bubble Lead. Use him as a toreador or matador uses a bull. After a direct hit, he flames up and turns into a three-stage fire missile, aimed at your last spot before his conversion. Leap over him and counter his attack with an immediate direct hit, which forces him to perform the same feat again. Continue this bullfighting technique until this "heat wave" dies down.

Quickman can be defeated by using his weakness (see "Quickman's Flaw") against him and/or using the Time Stopper (F) in the room. It hurts him to be slowed down or have his program halted. If you can successfully "super-charge" up (hold B until the flashing weapons meter changes from a yellow flash, to a light blue flash, to an intense white flash) the Atomic Fire (H) and hit Quick Man with it, he can be defeated in two hits, removing eight units of white-hot weapons energy each. Do not worry, as you have twenty-eight energy units in all.