I thought most standalone DVD players will play burned DVDs. I'm able to play burned DVDs and Blu Rays on all my devices. With the exception of Blu Ray players with Cinavia in the firmware. So far I haven't been stopped from playing burned Blu Rays, but I don't have any that are on the Cinavia list either. Someone please correct me if I'm wrong.
If you're talking about for copying/recording DVDs, yes they have encryption. For example, my parents have a Panasonic DVD Recorder. If we record something off of cable, and then I attempt to rip the DVD, it's all scrambled. Won't work.