The basic mechanic that this system runs on is pretty simple. You roll a number of d10s equal to your dicepool and look for matching sets. If you had a 10d pool and were running a race, for example, you could end up rolling and getting a set of two 10s and four 3s.
Now, how high the numbers are is referred to as the height, and how many matching numbers you got is referred to as the width. So, the first set would be referred to as a 2x10 set, and the second one would be referred to as a 4x3 set.
Height is how well you do whatever task you're setting out to achieve, while Width is about how quickly you accomplish the task. So, for the example, the 2x10 set would have you running really well, keeping your arms and legs in perfect form and just generally showing a lot of skill as a runner. The 4x3 set, on the other hand, would have you actually crossing the finish line faster, and might actually win you the race.
On the other hand, if you were taking a math test with those rolls, you would probably want to take the 2x10 set, because being the first one to finish the test would be less important than getting every question right. So some situations you wind up in might see you wanting to favor either Width or Height, depending on your rolls.
In combat, when you Attack, the Height of your roll determines which location you hit on your opponent, while the Width determines how much damage you do and how quickly your attack goes off.
When you Defend, your Height and Width both need to be equal or greater than the incoming Attack roll. If the Width is too low, your defense wasn't fast enough and the enemy gets a hit in before you can raise your guard. If the Height is too low, your defense just wasn't good enough to block your opponent's totally-rad attack. If the Width and Height are both equal or greater, each one of your dice neutralizes or 'gobbles up' one of the incoming attack dice. You can split up dice from your defense rolls as you wish among multiple incoming attacks, as well, so if you roll well enough, you can even completely block attacks from multiple opponents.
Ah, I see. Thank you. I think I'm starting to get the hang of it.
Also, my monster has a hybrid and full monster form, but is unable to fight in Hybrid form. Would I have to make Transforming a power, or can that be innate since it is a requirement of battle?
For something like that, I'd build it as splitting up your monster's parts between the hybrid form and the full monster form, and roleplay it so that you transform whenever using the monstrous parts. Here's an example of a similar monster concept taken straight from the sample npcs in the rulebook...
Lucinda, Susan's Monster
Appearance: Lucinds looks like a coifed Texas beauty queen aged to about 40, but her appearance is only skin deep--and that skin is a hard shell, covering a thick gooey filling that smells like concrete sealant and burns the skin. She's always smiling. And she always has cookies or brownies, fresh from the oven,even when there isn't an oven for miles.
Personality: Lucinda is Susan's new stepmom, and plays the part of "wanting to be her best friend" but sort of... wrong. She looks human, but hasn't gotten the hang of the subtleties. She talks in a slow Texas drawl, paints her nails every morning (drinking the leftover polish), and just wants to know everything about her new stepdaughter.
Favorite Thing: Cookies.
Way to Hide: Lucinda smiles wide and acts like a regular person. She even has a job substituting at her stepdaughter's school.
1-2 Hard Candy Shell 5d (Useful [blend in with regular folks], Useful [could seduce a saint], Awesome x2, Tough x2)
3-4 Graceful Hands/Tentacles 7d (Attacks, Useful [cooking, cleaning, baking!], Tough x1, Wicked Fast x1)
5-6 Long Shapely Legs/Pseudopods 8d (Defends, Useful [run like a steam engine], Tough x1)
7-8 Pulsing Goo-Sack 5d (Attacks, Useful [spray quick-hardening goo], Awesome x2, Tough x2)
9-10 Ovipositor 7d (Attacks, Useful [inject mind-controlling larvae], Awesome x2)