There are many different families present in Patriot Games. Each family plays a very important role in the plot and helps to drive the plot. The most notable families are the Ryan's, the IRA, the CIA, the miller's, and the royal family. The Ryan's and the IRA drive the plot the most of these families.

A faction of the IRA is initially responsible for the attack on the royal family that Jack Ryan thwarts. Wile he is defending the motorcade, Ryan shoots and kills one of the attacker's who also happens to be the brother of the other IRA member. Although the IRA is split over whether the attack was a good idea, they do not want Sean Miller to revenge his brother. Miller however is determined t do so and with the help of his fellow IRA members, escapes prison and is able to track down Ryan and his family in the US. Miller would not have been able to spring from prison and track down the Ryan's. His quest to revenge his brother and kill those that get in his way is dependent on the participation of his IRA family.

Jack Ryan on the other hand does not wish to act out on behalf of his family, he only tries to protect and do what is best for them. Initially, he even avoids returning to the CIA because he realizes he should be close to his wife and daughter. When he does return to the CIA, it is because his family was attacked and he wants to do everything he can to protect them. His decisions are always with their good in mind.

Families play an important role in Patriot Games. Whether nuclear or organizational, there are many families that drive the plot of the movie. They are the driving force in much of the plot and cause many of the problems that occur.