I Play Field Hockey, Soccer, and Tennis.
As I live in New Zealand we haven't had any FRCs yet. But I've had issues with VEX build sessions.
I'm dropping Soccer next year for many reasons - including Robotics.
This year we have a later regional which will clash with Field Hockey, but unfortunately I put Hockey first. My Head Mentor has said that I can take time off around games and practices (e.g. leave early before a game/practice then come late after)
Tennis will possibly clash with FRC when we start the official competitions but then I will just take a few hours off FRC each saturday morning and skip Tennis if we have a competition.
If we have a regional on a Hockey day, I will be utterly torn
but will quite possibly attend Robotics as there are far more chances for Hockey Games than Robotics competitions (inc. both FRC and VEX)