Stacking Movement Speed.

[Frogboy]

the way i believe movement speed is calculated is that it takes the highest value from each of five different areas:

armor
weapon
card
pot/badge
agi up/wind walk?

and then combines them for the overall speed boost effect.

that probably isn't clear the way i said that, so let me explain a bit better.
under armor, if you have multiple armors that boost speed, then only the highest in that category will be taken.

the same thing holds true for weapons, cards, skills, and pots/badges, though i am probably mistaken on the skills bit as i think agi up and wind walk do stack, just been a while since i've seen the effects separate.