What works on a train with a 12-year-old
A train gives you a seat, sometimes a table, and a connection that disappears every time you hit a tunnel. You are also in public. That rules out anything noisy, fiddly, or dependent on a stable signal. If your 12-year-old wants something to do, they usually do not want praise for participation. They want a game they can understand quickly and, ideally, use to beat you.
That makes head-to-head games the obvious place to start. Solo puzzles still have their place, especially if you are next to each other but not in the mood to play each other. But on a train, where the table is small and the time comes in uneven chunks between stops, simple turn-taking works better than anything sprawling.
That is the useful bit of Connect Four, Dots & Boxes, and Salvo in GameJar. They work on one phone or tablet, offline after one online visit, and they do not ask for an account. If you would rather hand the device over and read in peace, there are solo options too, but this is one of those places where playing together is usually less effort than trying to supervise boredom.
The prep, done before you leave the connection behind
Do this while you still have signal. Open GameJar once on the device you are taking. After that, the games are stored on the device and work in airplane mode. That matters on a train because the connection will fail at the exact moment somebody is finally paying attention.
It is also worth deciding, before you board, whether this is a shared-device trip or a hand-it-over trip. If your 12-year-old wants to compete, open one of the two-player games first. If they want to be left alone with a puzzle, open one of the solo games and move on. You do not need an account either way. A player profile is just a name and a colour, stored on the device.
One practical point. If you are at a table with other passengers nearby, pick games that are easy to pause and easy to read at a glance. You do not want to spend ten minutes reconstructing what was happening after tickets are checked and bags have been moved twice.
The games that fit this age and this setting
These are the ones that suit a train best for 12-year-olds, and why.
Connect Four, because it is direct and slightly ruthless
If your child wants to beat a parent, this is the cleanest option. The rules are obvious, the turns are quick, and a single round does not take long. That matters on the train, because interruptions are normal. You can finish a game before the next stop, or play a quick rematch if someone is determined to correct an injustice.
It also works well on a shared table. You are not spreading anything out. Nobody is balancing cards on a sandwich wrapper. You just pass the device back and forth. If there is only one child playing, there is also a computer opponent with three difficulties, which is useful if you have reached your daily quota of tactical defeat.
If you want the fuller rundown, there is Connect Four: How It Works | GameJar. If your main concern is patchy signal, Connect Four With No Wi-Fi | GameJar covers that part directly.
Dots & Boxes, because it looks harmless until it does not
Dots & Boxes is good on the train for a simple reason. It is quiet, compact, and turn-based in a way that suits a narrow seat and a small table. At first glance it looks like a basic line-drawing game. Then somebody gives away a chain of boxes and the mood changes.
For 12-year-olds, that is usually ideal. It does not talk down to them, and it is not random. They can work out traps, set them, and enjoy the moment you realise you have helped them. If the train is busy and you want something that does not attract attention, this is one of the better choices. It is all thought, no fuss.
Salvo, because the hidden board makes one device feel like enough
Some two-player games on one phone feel cramped. Salvo handles that better than most, because it is built around passing one device back and forth. Each player hides four ships on a 7x7 grid and tries to find the other player's first. There is a cover so the next player does not see the board.
That makes it surprisingly practical on a train. You do not need two devices. You do not need a stable connection. You just need a bit of honesty and enough room to angle the screen away from the other person for a moment. If your 12-year-old likes the idea of outguessing you more than outreacting you, this tends to land well.
It is probably better when you actually have the table, rather than when you are both wedged into airline-style seats with elbows already in dispute. But on a decent train table, it works.
Guess the Word, for when you need solo rather than shared
Head-to-head games fit this age well, but sometimes the parent needs to stop being part of the entertainment. In that case, Guess the Word is a sensible handover. The day's word takes six tries to find, and there are unlimited practice rounds after that.
It suits the train because each round is short and self-contained. If the ticket inspector arrives or you need everyone to move bags around, it is not a disaster. Your child can come back to it without needing to remember a complicated setup. If the connection has already vanished, that is fine too, once the device has had that first online visit. There is a more specific note on that here: Guess the Word With No Wi-Fi | GameJar.
If your 12-year-old is in a competitive mood, you can still make it shared by taking alternate rounds and seeing who solves in fewer tries. It is not built as a two-player game, but it does not mind if you improvise.
Playing together rather than side by side, if the situation allows it
On the train, side-by-side screen time is easy. One person scrolls, the other person stares out of the window, and everyone is technically occupied. That is sometimes enough. But if you have a table and half an hour, playing together is often simpler.
With 12-year-olds, the trick is not to make a ceremony of it. Pick something with quick turns and a clear win condition. Connect Four is the best first choice. Dots & Boxes is good if they like planning ahead. Salvo is the one to choose if they prefer hidden information and a bit more suspense.
The social advantage is obvious enough. You are both occupied, but you are occupied by the same thing. The practical advantage matters more on a train. One device is easier to keep charged, easier to put away quickly, and less likely to become a negotiation about whose turn it is to use the better seat-side charging socket.
GameJar is useful here because the games are simple to start, free, and have no ads appearing at exactly the wrong moment. That matters more in a quiet carriage than any grand theory about wholesome family time.
Off-screen fallbacks for when the device has to go away
Sometimes the battery is low. Sometimes the train is arriving. Sometimes you just need the phone back. It helps to have a few off-screen options ready that work in the same space.
One is the category game. Pick a topic, then take turns naming items in it without repeating. Capital cities, dog breeds, things in a supermarket, football teams, kitchen equipment, whatever is likely to be taken seriously. If the answers start getting suspicious, that is part of the format.
Another is twenty questions. One person thinks of a thing, the other asks yes-or-no questions. It works well on trains because it is quiet and needs nothing except a willingness to be exacting about the rules.
You can also play odds and evens with the carriage around you. Guess whether the next station announcement will come before or after a tunnel. Guess whether the person opposite will stand up at the next stop. Keep it harmless, keep it quiet, and do not involve strangers in your entertainment without their consent.
These are not part of GameJar. They are just useful to have when the screen has to disappear and you still have twenty minutes left.
The short version
If you are on the train with a 12-year-old, assume the connection will drop, the table will be small, and they would rather win than be indulged. That points you toward quick, clear games with short turns and no dependence on signal.
Start with Connect Four if you want a straightforward match. Use Dots & Boxes if they like quiet tactical games. Pick Salvo if the table is usable and passing one device back and forth sounds manageable. Hand over Guess the Word if solo play is the better option.
That is the main point of GameJar on a trip like this. Open it once before you leave, then it keeps working when the train goes underground and your connection gives up. Which, on trains, it will.
FAQ
Do these games work on the train with no signal?
Yes. After one online visit, the games are stored on the device and play in airplane mode. So if the connection drops in tunnels, they still work.
Do we need an account before we travel?
No. No account is needed to play. A parent can optionally sign in to sync scores across devices, but nobody has to.
Which game is best if my 12-year-old mainly wants to beat me?
Connect Four is the simplest choice. It is quick to learn, quick to play, and clearly competitive. Dots & Boxes is also good if they like a more tactical game.
Which one is best if we are sharing a small table with other passengers nearby?
Dots & Boxes and Connect Four are the least awkward. They are tidy on one device, easy to pause, and do not require much screen privacy.
What if they want something solo instead?
Guess the Word works well for that, especially on a train, because rounds are short. You could also hand over 2048 or Mini Sudoku if they want to get on with something by themselves.