The probability of invention success is dependent on the following:

•Factional Encryption Methods skill level
◦0.01 multiplier per level up to 0.05 (E)
•Skill level in the appropriate scientific fields (eg. mechanical engineering)
◦0.02 multiplier per skill level up to 0.2 (F)
•Metalevel of the optional base item
◦Modifies the scientific field modifier by a factor of 5/(5 - metalevel) = (I)
◦Metalevel 0 (Unnamed Tech I items) does not improve invention probability. (I = 1)
◦Metalevel 4 items give the greatest benefit (I = 5)
◦Metalevel 5 and greater (Tech II and storyline) cannot be used.
•Item Being Researched (Base)
◦Modules and Ammo have a base probability of 40%
◦Frigates, destroyers, Skiff, freighters have a base probability of 30%
◦Cruisers, industrials, Mackinaw have a base probability of 25%
◦Battlecruisers, battleships, Hulk have a base probability of 20%
•Decryptor modifier
◦See above for probability multipli