Morality and ethics are central to the messages in The Kill Order. They teach each other, occasionally talk about women, and take their roles as the guardians–as 'men'–very seriously. At the same time, the old soldier Alec also learns from the youthful Mark. Mark learns a lot from Alec, following much of the old soldier's ways. He is able to become more courageous because of his love for his friends and for Trina. Throughout the story, Mark always tries to braver, and he does in fact become a braver individual. Tied in closely with the idea of gender roles is the concept of what masculinity is.

At the same time that The Kill Order confuses gender roles, it also sees its characters conform to traditional conceptions of gender roles. Not only are they the ones 'pursuing' the women throughout the story, but they are also pursuing them to rescue them. Mark and Alec spend a lot of time together as they undertake a lot of physical action, and protect their female friends quite a lot. The idea of gender roles is relevant in The Kill Order. Regardless, fate continues to bring them together. However, with the onset of the flares, Mark sometimes wonders if they are only together because everyone else they know is dead. For example, Mark had always had a crush on Trina, but was never able to really able to make her view him in the same way.

Tied along with unpredictability is the idea of fate, or the way things were always intended to occur. The unpredictability of the human world means that anything can happen to the ones he loves, and Mark must be ready to take unprecedented actions accordingly. When things happen, Mark and his friends have to adapt, adjust, and act accordingly. At the start of the story, Mark has no idea what will occur that day. One day he is on the subtrans, and the next moment, sun flares strike–he and Trina are thrown into flux. Unpredictability is a central, recurring part of Mark's life.

The kill order by james dashner