Critics have pointed out The Iron Trial’s significant similarities to J. K. Rowling’s Harry Potter series. Like Harry Potter, Call learns that he has magical abilities and is sent to a mysterious, magical boarding school, where he learns to control and use his magical abilities. As in the case of Harry Potter’s Hogwarts, The Iron Trial’s Magisterium is a well-guarded secret from non-magical individuals, as are the respective magical worlds more broadly; magical individuals live secretly within the non-magical world. Furthermore, in both stories, magic most often emerges in the children of magical individuals but can occur in families with no other magical members. Both schools manage to contact these non-magical families and ensure that their children are allowed access to a magical education.

Furthermore, the two series share similar characters. Jasper is immediately presented as a haughty antagonist who makes rude remarks to Call, much like Harry’s competitor and antagonist, Draco Malfoy. As in Harry Potter, Call conquers Jasper in tests of the students’ skills and abilities, conforming to the trope of good triumphing over evil. Furthermore, like Harry Potter’s Hermione, Tamara is a high-achieving and ambitious female student who eventually learns that breaking rules is sometimes necessary in the pursuit of good.