There is no single study behind this
Despite the title, this is not a report on one research project, and no invented numbers appear here. What follows is practical, general advice on self-discipline: the ability to act on your intentions even when something more appealing is available. Research on self-control is itself still debated, so treat the ideas below as things to test, not guarantees.
Self-discipline is mostly about setup
People often picture self-discipline as gritting your teeth in the moment. In practice, many people who seem disciplined have simply arranged their surroundings so that the intended choice is the easy one. Games are designed to be engaging, so relying on willpower at the exact moment you want to keep playing is a hard way to go. It usually works better to decide ahead of time and to make the plan visible.
Two decisions: starting and stopping
Most struggles with play come down to two moments.
Starting. Sometimes the problem is beginning a session when something else should come first, such as homework, chores or sleep. The urge is strongest when the game is one click away.
Stopping. More often the trouble is ending. Each match, level or quest finishes with a natural pull toward the next one, which is the feeling behind the one more round urge.
Treat them separately. The tools that help you start later are not quite the same as those that help you finish.
Tools for starting well
Put something small before play. A short task, such as clearing your desk, making a meal or answering one message, creates a gap between the impulse and the game. Many people find that the first few minutes are the hardest and that the urge fades once they are busy.
Add friction. Log out after each session. Keep the console in a shared space. Move the game icon off your main screen. Small barriers do not stop you, but they give you a moment to ask whether you want to play right now.
Decide the “when” in advance. A plan like “after dinner, for about an hour” is easier to keep than a daily negotiation with yourself. The idea of session planning is covered in more detail on this site.
Tools for stopping well
Pick the stopping point before you begin. “Two matches” or “until this chapter ends” is easier to honor than “until I feel done,” because you will almost never feel done in the middle of something absorbing. See the guide on stopping points for ideas.
Use a timer you control. A timer set at the start works as a neutral reminder instead of a nag. Some people do better with a gentle alarm placed a few minutes before the planned end, so the final match can be a deliberate last one. The page on play timers covers using them without resentment.
Pair the ending with something else. If the next thing on your list is pleasant, such as a meal, a call with a friend or a walk, stopping feels less like a loss. If nothing appealing follows, the pull to stay is stronger. Choosing non-gaming rewards helps here.
Have a shutdown ritual. Closing the game, saving, writing one line about where you stopped and standing up gives your mind a clear signal that the session is over. It also lets you pick up later without feeling you must finish now.
Routines and cues
A cue is anything that reminds you of a plan: an alarm, a note on the monitor, a sound that signals dinner, a roommate who agrees to knock at a set time. Cues work because they do not depend on remembering or on motivation in the moment.
A routine is a repeated sequence that turns choices into habits. Habits take effort at first and typically become easier with repetition, although how long that takes varies a great deal between people. You do not need an elaborate system. One reliable start cue and one reliable stop cue are enough to begin.
When you slip
You will sometimes play longer than planned. That is normal. What matters more is what you do next. Harsh self-criticism tends to make people avoid thinking about the problem, which makes it harder to fix. A calmer approach is to notice what pulled you in, adjust one thing in your setup and carry on. The article on habit slip-ups goes into this.
Keeping the whole picture in view
Self-discipline works best when it serves something you actually want. If your plan feels like punishment, it is unlikely to last. Ask what you would like your days to look like, such as enough sleep, time with people you care about, progress at work or school, and room for play you enjoy. Then let the limits support that picture.
If you find that, despite sensible plans, you cannot stop, or play is regularly crowding out important parts of your life, this is not a character flaw to fix with more willpower. Consider talking with a qualified professional. This article is general information and not a substitute for that kind of support.