Simple RAW Thread for 3.5 #35: 3/2 Score And Four Threads Ago

[St Fan]

Q 641

How does the Shadow Blade Technique work? Do you use 1d20 to make an attack roll or a 2d20 to make an attack roll?

A 641
The description is quite clear about it: you roll 2d20, then select which of the two results to use.
If you rolled low on a die and high on the other, you pick the higher result, increasing the overall chance to hit normally.
If you rolled high on both dice, you can pick the lower result; if this roll is indeed enough to hit, you do normal damage plus 1d6 cold damage.