I have a question for the legal types on board. I'm thinking of buying a mat to have some guys (jiu jitsu) come over to my house and roll. With that comes some liability. I have an umbrella policy that exceeds my net worth, I would only be rolling with friends/people I trust, and I would have them sign a disclosure to hold me harmless for potential injuries. Knowing this, does it seems reasonable to have this kind of activity going on at my property? If not, what are the alternatives? City park, etc? Thanks in advance.