Board Thread:Questions and Answers/@comment-47.91.20.245-20180822055025/@comment-26447088-20180822125612

CTA Skill Boost basically means that the skill with it in the description has a higher proc % in FF/CTA. CTA Boost (S)=+5%, (M)=+10%, and (L)=+15%.

So if you take D'Artagnan (Halloween)+4 for instance (using him as an example because he has double CTA Skill Boost skills), his Rush would have a base skill % of 30% in FF/CTA (25% + 5% from the CTA Skill Boost (S)), but everywhere else it would be 25%. His Multi would have a base % of 40% (25% + 15% from CTA Skill boost (L)). By base %, I'm referring to before purification bonuses and buffs from units like Meru (Christmas) and Salix (Remix) that boost skill % visibly.