Choose your next game around an ordinary evening, not just the number of hours you might eventually spend finishing it. A campaign's total length cannot tell you whether tonight will contain a satisfying stretch of play. For that, the more useful question is how much uninterrupted time you have and what you want to accomplish before stopping.
Imagine two players who each have three hours available in a week. One has four reliable 45-minute evenings. The other has a single uninterrupted Saturday afternoon. Their total time is identical, but they shouldn't automatically make the same choice. One needs a game they are happy to put down repeatedly; the other can settle into a longer stretch without watching the clock.
A long adventure could suit those evenings perfectly. A much shorter game could be a poor fit if the part you want to experience requires more attention than you can comfortably give it. Choose the session you want, then consider how many of those sessions you would like.
Start with the time you actually need to stop
Suppose you can begin at 9:15 and need to finish at 10. Treat 10 as the end of playing, not the moment to start looking for somewhere convenient to leave. You might aim to reach a stopping point a few minutes earlier, with room to finish a conversation or confirm that your progress is retained. The exact buffer is your choice; spending every available minute before considering the exit leaves none.
Before buying for that window, look for clear official information about stopping and resuming. Can you leave during the activity you expect to play, or only after completing it? What would you have to repeat? An unanswered question should remain unanswered in your purchase decision. Don't assume that a short advertised activity guarantees a short session for you.
Your preference matters alongside the technical answer. You might be perfectly happy to stop halfway through exploring a building. You might dislike breaking off a dramatic conversation even if the game permits it. Being able to leave and feeling satisfied when you leave are separate considerations.
The same applies to interruptions. Forty-five minutes you can protect is a different offer from forty-five minutes during which you may need to step away without notice. Choose for the less predictable version if that is the evening you actually have, rather than planning around an uninterrupted session you cannot promise yourself.
Decide what would make a short session worthwhile
A fixed window doesn't have to mean an easy objective or a guaranteed win. It does require an ending you can accept without winning.
Consider a hypothetical player learning a difficult boss fight. They might decide to spend half an hour practising how to recognize one attack, then stop after the next attempt. That gives the session a purpose even if the boss survives. “I'll stop when I beat it” offers no comparable boundary. Making the stopping time depend on an uncertain result is the risk to your schedule, however difficult the game is.
Another player might want a complete story scene, a finished mission or a match with a clear result. That is a reasonable preference too. If an unfinished objective would leave you frustrated, give that preference weight instead of insisting that any amount of progress ought to feel rewarding.
This is also why genre alone is a weak shortcut. For the decision at hand, ask whether the particular activity can give you the kind of ending you want. Don't reject an ambitious adventure solely because its whole campaign is long, or assume a compact game will fit neatly into every spare half-hour.
Keep some games for a different kind of evening
There is a cost to optimizing every choice around short sessions. You could exclude the experience you most want: a long, absorbing stretch in which you stop thinking about the clock. If that is the appeal, protect a suitable evening for it rather than squeezing it into an unsuitable one.
For a new game whose stopping points you don't yet understand, a flexible first session would let you find out without testing an important deadline. Afterwards, you can decide whether it belongs in the weekday window or the longer weekend slot. You can keep a game you love for a time when you can properly enjoy it.
Before choosing tonight, picture the moment you need to put the controller down. Would you be content to stop where your planned activity might leave you? If the answer depends on finishing one more thing, allow more room or choose something else. A useful measure of fit is whether you would want to repeat that kind of evening, not how quickly it moves you toward the credits.