Some gaming competitions require that you have a breast collar, so ask local riders in your area so you won't be caught off guard when it is your turn to run.
Really? I have never been to any type of horse event anywhere that required a breastcollar, or you would be disqualified. Interesting to know! I mean, technically, I've been to ropings where there is no where in the rules that it states you must have a breastcollar. Obviously, no one is going to rope without one though.
Although that really seems like a silly requirement to me. If your saddle fits well and doesn't slide back (when doing speed events) you really don't have to have a breatcollar then. My mom doesn't use a breastcollar on her horse, because her saddle fits well and she feels her horse runs more freely without one.
What else does this association require, tack-wise?
However, I do agree with the "what if" protection of the breastcollar if your cinch would happen to fail. At least your saddle won't roll completely under the horse, possibly hung up on the back cinch (if you have one). I have seen that happen at a horse show where the billet tore and the breast collar was the only thing that prevented the saddle from going under the horse, possibly preventing a huge wreck.