If there is money changing hands or its advertised somewhere its risky.
If they want to they can bust you. Google bridge playing pensioners pattaya. Was just a meeting playing bridge they got busted under gaming act. Had a friend who was legally working here as dive instructor and used to be part of a sunday night jamming session they got busted for passing the hat around for drinks for the band. Admititly one of the band members had upset a local pokiceman, but they got arrested and i think two of them deported.