Board Thread:Game Discussion/@comment-29726080-20180115175156/@comment-32545704-20180115190028

It was changed some time ago so you can only have 3 mechanics, but those who already downloaded the game were able to keep the old system. The only way you could switch it now is to steal your son's tablet.

This thread has some info

http://rr3.wikia.com/wiki/Thread:216232