One mouse, two people
Sharing a single mouse without a tug of war: turn rules, disabling tap-to-click, and what to do when it freezes.
In a house with exactly one mouse, every game that needs a cursor becomes a two-person game in a different way: one person holds the mouse, the other waits. That arrangement works, but only if both people agree before the round who holds it, because tugging a mouse mid-round is the fastest way to ruin both the turn and the mood. Say it out loud before the first round, because a rule that lives only in one head is not a rule.
The first thing to know is that one window has one cursor. There is no way for two people to steer a mouse inside a single game frame, even with two mice plugged in. The operating system merges both into one pointer, so two people pushing at once produce a jerky motion that neither of them controls. Two pointers on one desktop is a different matter, but inside a single game frame there is only ever one.
So take turns, and count turns in rounds rather than in seconds. The person holding the mouse plays a full round while the other sits outside with the score sheet. Then you swap, and the person who just won hands the mouse over first, since the winner usually has less explaining to do. That rule is small, and it removes the whole scene of two hands landing on one mouse.
When you pass the mouse, lift your hand clear before moving it across, rather than sliding it along the desk. Sliding sends the cursor racing across the screen, and if you happen to be on a level select screen it is very easy to click the exit button by accident. One second of lifting is far cheaper than reopening the game from the start. Pick the mouse up by the sides rather than the palm rest, which is the part that collects sweat.
If the machine is a laptop with a touchpad, disable tap-to-click before you begin. With two people sitting close, anybody wrist can brush the pad and produce an unintended click, which either steals focus from the game frame or presses a button nobody meant to press. Turn that off in the operating system mouse settings, or tape a small piece of card over the pad. Some laptops also have a shortcut key that disables the pad completely, which is faster than digging through settings.
Keyboard-only games are the right choice whenever two people are present. That is why this bench keeps a section for games split across a keyboard: nobody waits for the mouse there, and both players are in from the first second. If the evening offers only one mouse, start with a round like that and move to cursor games once both people have found the rhythm. That section exists for exactly this situation, and it is where most evenings here begin.
Another option is letting the person without the mouse work the keyboard inside the same game. Many action games allow one player to aim with the mouse while the other moves with the keys, or the other way round. It works, but say out loud who does what before starting, because if both people believe they are driving the character, the character will simply stand still and spin. Say the words out loud once, then start, and the round will be cleaner.
If the mouse freezes mid-round, do not unplug it straight away. Wait three seconds, click once in the middle of the frame, and try again. Most freezes inside a browser come from the frame losing focus rather than from failing hardware. Unplugging in the middle of a round only costs more time and sometimes costs the browser its state as well. Unplugging a mouse also resets any custom button mapping the system had stored for it.
Finally, put the mouse in the middle of the desk instead of at one edge. In the middle both people can reach it without leaning, and passing it takes less effort. A detail that small changes the shape of an evening, especially when two people play five or six rounds in a row without either of them standing up. It is a small thing to set up, and it removes one more reason for somebody to lean across the desk.