Originally Posted by
Troacctid
Oriental Adventures is a D&D sourcebook published by Wizards of the Coast. It was published during the 3.0 era and later updated to D&D 3.5 in Dragon 318. Rokugan Campaign Setting is a d20 Rokugan sourcebook published by AEG. Totally different book. Since it uses the d20 system, it's compatible with D&D, which puts it in the same league as d20 Modern, d20 Star Wars, and Ponyfinder.