Mega Man 3's password system may look pretty complicated, but it's actually pretty easy to figure out. For example, it uses the placement of a single red dot to record how many Energy Tanks you have, and you can totally use this to your advantage.

For example, take this code that I got for having beaten no Robot Masters and having no Energy Tanks.

Consulting the chart below, I know that a single red dot in square C5 means 0 Energy Tanks. From there, it's a simple matter of moving that dot up to A6

To start the game with 9 Energy Tanks, the maximum!

From there, it's a simple matter of recording your password, moving the dot, and continuing on each time you need a refill!

And here's the list of dots and their Energy Tank attributes

      #   Dot Position
0      C5
1      E6
2      E4
3      B4
4      A5
5      C1
6      D2
7      C3
8      F2
9      A6