The beautiful thing about Christmas traditions is that we do them every year. The terrible thing about Christmas traditions is that we do them every year. A drinking game (or non-alcoholic equivalent) can be just what you need to add a little spice -- or sauce -- to the annual proceedings.
At some point, my husband (and I, I guess) decided that we would start two family traditions: every Christmas, we watch one of the Mighty Ducks movies and one of the Star Trek movies. This year -- for D3 and The Search for Spock -- I'm going to use what we've learned through our viewings so far to, well, gamify the experience.
At the heart of a drinking game is love for repetition and cliche. Like this Hallmark Movie drinking game that's been making the rounds, all drinking games boil down to identifying the tropes of a movie, TV show, or genre. It's perfect for Christmas movies and movies you've seen a million times. (You can also always make a drinking game for family dinner -- every time someone says "Trump," finish your drink -- but you'll probably want to keep it between you and your cousins, and on the DL.)
Done right, this won't have you drinking more than you would otherwise, just at more regimented times. If you don't want to drink, you can use candy -- and, as with alcohol, eventually end up loopy and with a stomach ache -- or you can make bingo cards. (If you google "bingo card generator" you'll find a ton of options, but this can also be a craft project.)
For a drinking game, a key is variety -- based on how common an occurrence is, it can earn a sip, a gulp, or a finish-your-drink. Pick enough prompts that you'll be busy (and stimulated to pay attention), but not more than you can remember to look out for.
Let me share one caveat from the too-effective drinking game my friends and I once made for watching The Tudors: if you're doing this for a TV show, set a house rule to discount the "previously on..." catch-ups. They tend to compress everything that makes a show itself, and god, that can get rough.