I'll mention two things here (but hint you'll find out alot more at our forums and blogs)...
1) Task Resolution
When you make a task check, you roll one or more d20s, as determined by the nature of the check (see Attribute Checks and Skill Checks, following). Every task check is rolled against a target number (TN). If the die result is lower than or equal to the TN, your character succeeds at whatever he was attempting to do. If the die result exceeds the TN, he fails.
You make an attribute check whenever your character attempts an action that directly relies on an innate human quality, rather than leveraging a set of learned or trained capabilities. Specific circumstances call for checks with each attribute, as detailed in the attribute descriptions. Every attribute check is a 2d20L roll. The base TN of each attribute check is the attribute’s value.
A skill check involves rolls of a variable number of d20s, depending on your character’s rating in that skill. Each task is associated with a single relevant attribute. The base TN of the task check is equal to that attribute’s value.
Skill Ratings:
Value Rating ---- (Dice Rolled)
64+ ---- Legendary (6d20L)
32-63 ---- Master (5d20L)
16-31 ---- Expert (4d20L)
8-15 ---- Professional (3d20L)
4-7 ---- Competent (2d20L)
1-3 ---- Novice (1d20)
0 ---- Unskilled (2d20H)
BTW, most starting 20-30 year olds mostly have Competent and Professional skill ratings, with 1-2 Expert is they are lucky.
We had a competition amongst the designers and playtesters to come up with a character with a single Legendary skill and the only winning entry was a 60 year old (IIRC).
2) Reflex System in general
Individual play groups often use “house rules” to tune their game systems to a specific preferred level of complexity and realism. To facilitate this, we’ve written the Reflex System with three stages of rules. This book is written with a default level of Stage II in mind. However, scattered throughout the text, sidebars and optional rules sections will highlight ways to simplify or enhance the rules for Stage I or Stage III complexity. Future supplements will also provide additional focused rule sets for Stage III play.
Stage I
Basic. Stage I rules are the minimum necessary to numerically define a character and play a fast-running game. Stage I rules tend to boil fairly complicated events down to simple abstractions. This level of complexity is recommended for introducing novice players to the Reflex System and the world of Twilight: 2013.
Stage II
Standard. Stage II rules contain a default level of complexity that strikes a balance between speed of play and realism. The complete Stage II rules set incorporates all of the systems that we consider essential for capturing the realities of survival in a post apocalyptic environment.
Stage III
Advanced. Stage III rules are written with the hardcore wargamer in mind. Stage III rules provide extra, often gritty, details of various aspects of play. However, Stage III play does tend to require a greater amount of bookkeeping and number crunching.
Hope this helps.