You'll notice that stats are provided as numbers, but these are actually dice. For example, if your Strength is 6 and I ask you to make a Strength roll, you will roll D6. If it's 12, you roll a D12. Yes, sometimes you'll be rolling a D3, a D2 or even a D1. Of course, you almost always roll the doubling die with it. Note that there is no maximum for these stats. They can get arbitrarily high (although it will cost you a lot of AP). Oh, by the way, the notation D6 means a doubled roll, while a d6 is a non-doubled roll. Get used to that.

Meta is what you use to do neat stuff, like Meta Enhanced Rolls (MERs). You generally need Mastery to be able to use Meta. For example, Relena has Mastery in the plasma sword. Normally, she rolls D10 for damage, but if she spends a Red Meta (written @R), she rolls D12 instead. Meta can also be used to modify actions in different ways. Relena has Mastery in the feat Blade: Blade's Advantage. Without spending Meta, this allows her to roll a d6 with each attack, and a roll of 6 doubles attack and damage for that strike. If she spends a Yellow Meta (@Y), then she can roll a d4 instead, and double attack and damage on a 4.

Meta comes in five colours - Red, Orange, Yellow, Green and Blue. The first five colours of the rainbow. Each is more powerful than the one previous. An Orange Meta is better than a Red Meta. You can spend a Meta of a higher colour to get the advantage of the lower colour, but you can't spend multiples of the lower colour to get the advantage of a higher. You can't spend two Red Meta in place of an Orange, for example.

Meta is cool. You'll like it.