There are times when it may be appropriate to temporarily change the die type rolled for your clichés due to the physical size of your character. Sometimes, it's good to be a giant, sometimes, it's good to be a small.
In most cases, the GM will simply adjust the target number (a 50′ chasm is no challenge for a Colossal Giant (3), but it will be quite the feat for the vertically challenged (dwarves, etc.). However, what do you do when the aforementioned giant wants to arm wrestle a dwarf?
In cases like this, I recommend modifying the die used for the cliché. For the purpose of the contest (and this only applies to contested actions), the GM may modify the die rolled for each cliché (either up or down depending). The character which is considered to be at a disadvantage will roll a d6 (as normal), and the character with the advantage will roll a higher die (GMs discretion).
While size issues may not come up often in a game (depending upon the campaign and the size variation of the players), it doesn't hurt to be prepared (realize that the GM may require you to either double pump or use funky die for such a cliché to begin with).