[FAQ]: Can I have multiple robots?

Q: Can I build a second robot, perhaps to use one exclusively in the Skills Challenges

A: No. Only one (1) robot will be allowed to compete per team in the VEX Robotics Competition. Though it is expected that teams will make changes to their robot at the competition, a team is limited to only one (1) robot.

This Q&A entry has more discussion on the illegality of additional robots.