Deku has proven to be exceptionally intelligent on many occasions.
He has also shown to be a quick learner, which has helped him figure out most of One For All's mechanisms in a short period of time and work around its limitations. He has displayed keen observation and analysis skills, coming up with a plan to escape dozens of villains when he was trapped on a boat. It's usually his intelligence that has helped him more than his Quirk. Gran Torino even complimented his intelligence, saying that Deku is the kind of person who thinks before he acts. His grades are one of the highest in his entire class, showing that his constant training with One For All doesn't interfere with his studies. Deku also possesses a borderline encyclopedic knowledge of superheroes, villains, and the overall world he lives in, making him resourceful as a result. His time at U.A. High School has helped him develop his own signature Shoot Style,
allowing him to fight on par against opponents with many years of experience)