How can you get an adult dog to learn to play games?

Dogs can be taught that playing is inappropriate. Here is my advice. If you dog likes food you can start with a cheap plastic tupperware that is about the size of a ball. Put food inside of it pop some holes in it to let the food smell to come out. Shake it in front of them, let them sniff, it act as if it is the greatest thing in the world. When they are highly interested throw it out. All you are lloking for is for them turn towards it, watch it, go forward towards it. If they don't respond you run up pick it up act as if it is the greatest thing in the world. This will take some time but you can teach them to play you just have to find out what motivates them. You can also try taking an old tube sock and putting food in it. Same thing it is the greatest thing ever. If you are trying to teach tug... not all dogs tug hard and remember that if you play a game and never win it isn't fun. So those dogs who aren't varicious about dont pull it out of their mouth and let them win it. Hope this helps. Remember excitement breeds excitement.