A co-op game should tell you what happens to your progress when the evening ends. Before asking friends to buy it together, its store page should explain whose save holds the campaign, what a guest keeps, and whether the group can continue when the usual host is absent. In our view, those are basic buying details.
Getting everyone into a lobby is only the beginning of playing together. The more useful question is whether you can arrange the second session without repeating work or leaving someone behind. That deserves a plain explanation before you commit to a shared campaign.
Plan for the evening someone misses
Imagine three friends starting an adventure on Friday. One person creates the session, everyone completes two chapters, and they agree to return the following week. Then the host can't make it. Can the other two carry on? If they do, what will the absent player encounter when they return?
This is a hypothetical buying situation, not a description of a particular game. But it's a useful question to put to any co-op campaign. A single shared world, separate character saves and individual story progress are different arrangements. None should be inferred simply from a promise that you can play with friends.
Nor should "your progress carries over" be the whole explanation. Which progress? Keeping equipment would be useful, but it wouldn't answer whether you need to repeat the same mission in your own campaign. A completed chapter wouldn't tell you whether a consequential story choice follows you home. Spell out each part that affects what the player does next.
For a group that always plays together, a campaign attached to one host might be perfectly acceptable. Agreeing who hosts and reserving that save for the group could make the arrangement easy to understand. For friends with changing schedules, the same restriction could make the purchase a poor fit. The rule matters because the groups need different things.
Shared progress needs consent
It would be tempting to demand that every action automatically counts for everyone. We'd prefer something more careful: clear rules and a choice where a shared decision could overwrite a personal one.
Suppose you join a friend much further into an imaginary story. You might want the rewards from helping without skipping the chapters you haven't played. Or you might be delighted to treat the shared session as your own progress. A good explanation should make it possible to distinguish those intentions before anything permanent happens.
The same goes for major choices. If the group destroys a village in its shared campaign, importing that outcome into your separate adventure shouldn't be an obscure side effect of accepting an invitation. A confirmation that names what will change would be much more useful than a vague warning about synchronization.
There are reasonable limits to this argument. A deliberately shared world needs a consistent history; it can't promise every participant an incompatible version of the same event. A game built around one continuous group may reasonably ask that group to stay together. We aren't arguing that every design should support every schedule. We are arguing that its expectations should be visible before purchase and understandable during play.
That also leaves room for a guest who simply wants to help. Not everyone needs a personal copy of the entire campaign. A clearly described guest role is a fair offer. Discovering the limits after several evenings is a much less appealing introduction to them.
Ask these questions before buying together
If you're organizing the next group game, look for answers to four questions in its current official support information: who owns the campaign save, what guests retain, whether another player can host the continuation, and how the game handles different points in the story. Check the edition and platforms your group will actually use rather than assuming an answer applies everywhere.
Then agree on one practical rule for your group. Will you wait for everyone before advancing the story? Can people develop their characters separately? Who keeps the shared save? Even a flexible system benefits from an agreement about spoilers and missed sessions.
If the documentation doesn't answer a question that could break your plans, treat that feature as unconfirmed. Don't turn "we couldn't find a restriction" into "it must work." Choose a game whose documented arrangement fits the evenings your friends can realistically share.
Developers don't need a clever label for this. They need a short, specific explanation of what each player gets to keep and what the next invitation will load. When you're buying a game together, knowing how you can continue together should be part of the offer.