Each applicable Relic has three types: Wrecked, Malfunctioning, and Intact. These three types are used to establish a "base probability" in the calculation on success rate (i.e. the percentage of attempts resulting in a subsystem BPC) and a predetermined production run count:
- Wrecked relics have a base probability of 20% and a run count of 3.
- Malfunctioning relics have a base probability of 30% and a run count of 10.
- Intact relics have a base probability of 40% and a run count of 20.
The formula for RE success probability is:
success rate = base rate x [1 + reverse engineering skill level x 0.01] x [1 + (datacore 1 skill level + datacore 2 skill level) x 0.1]
As you can see, the skill level for Reverse Engineering is dramatically less important than the datacore skills. As such, I advise minimal required training on RE and max skilll levels on your datacore skills.
Here is a GoogleDoc link you can use to save locally to calculate your success probability.
As an example, if you skilled RE to 3 and both datacore skills to 3, then your success probabilities would be:
Taking the extra time to get just those datacore skills to 5 (leaving RE at 3) would be:
The actual RE job itself, if successful, will randomly produce any one of the four subsystems for that particular relic, which means you first cross your proverbial fingers that the RE job is successful, then again cross them that the desired BPC has resulted. I cannot count how many times I have cursed a successful RE job that provided me with a useless BPC!
FYI - Here is a great reference page for EVE Formulas