Hello ChosenUndead! I notice that this post is over a month old, but for your future DnD itches I would highly recommend this project that is near and dear to our hearts. The Aurora Point Institute is a West Marches styled campaign that has been running for the last year and a half with over 70 active adventurers. We have an overarching World Story that updates every 2 months with 'World Events' and each chapter ending with a 'World Event Mission' that includes as many adventurers as possible over a series of games played over a weekend usually. Outside of the World Story there are dozens of DM Run Stories & Plotlines throughout the world of Aspirion, the stories interweaving and working together to build a wild and flourishing world for you to explore through an expansive text-rp world. So even if you only have 30m to play during the week you can Roleplay your character interacting with others, purchasing gear, progressing plot points, or just sitting back and enjoying a drink at the Institute's all-inclusive restaurant. A player-driven game listing system allows you to post a game listing for a time and a level that work for you and let others join up! We have games during both AM & PM all week long with investments into both PBP & roll20 + Discord VC as mediums. I think this style might sate your need for drop-in DnD when your party is otherwise busy. You can use our forum post here to navigate to our discord server as you wish!
