It is an expression using the word "pull" for whatever reason. "They use tricks against you." For example: If someone replaces your milk with cream, that's a trick, so they "pulled a trick on you". It usually refers to when you make a trap or set something up instead of just lying to them.

They pull tricks on you= They play tricks on you.

It means that "they" (3rd person plural) are tricking or pranking you.