What belt level should you start training leg locks at?  It depends a little bit on what your goals are and whether you're doing gi or no gi, but it's a lot sooner than you think EVEN if you're competing only in the IBJJF rule set.  This podcast episode is excerpted from a 17 minute long Youtube video at https://www.youtube.com/watch?v=7GQZPtpsg_U which takes you through how to do the actual leglocks and demonstrates some of the techniques that will instantly get you disqualified from an IBJJF tournament.