The async multiplayer from the game 9 Kings would be a perfect add-on to Battlegrounds
I picked up the game 9 Kings a while back. If you're not familiar, it's a rogue-like auto-battler where you draft / buy cards each turn to improve your warband. Has some similarities to Battlegrounds in that way, although it takes place on a 2d grid where adjacency is important.
Anyway, the game was always single-player until the devs recently put out an asynchronous "multiplayer" update. I put that in quotes because instead of battling against other players live, you battle against their past runs. In other words, the game picks 8 saved runs for a tournament, and each turn, you play against one of those runs, as it existed during that particular turn. The other runs play against each other as well, and ultimately one is the tournament winner.
The game has some balance issues, but the format itself works surprisingly well. I can't stop thinking about how much I would love a Battlegrounds version. You know why? Because there is NO TIME PRESSURE! The game doesn't care how long your turn takes because nobody else is waiting for you. You can pause, wander away, and come back in three weeks to finish the run. There's no rope.
There is also no waiting for your next turn! It's addictively quick, especially in those early turns where you don't have much to do.
Now, there are trade-offs. Most importantly, the other players will not tech to defeat your board, because their run already happened. It isn't a huge issue in 9 Kings since counter-play is limited, but it would be a big change for Battlegrounds. In my opinion, the final match-ups that go back and forth based on tech choices are probably the most exciting thing that happens in this game.
That's why I would propose this as an add-on to, not a replacement for, the live experience. Battlegrounds is great, but sometimes you just can't guarantee 20+ minutes of uninterrupted playtime. Having what is essentially a single-player, untimed version of Battlegrounds would be perfect to scratch the itch without having to commit to a run. It also allows for "casual" mode, where you can try out new builds (read: play while drinking) without risking any rank points.
Thoughts? Have you played other games with a similar saved-run multiplayer mode?