Two pens on one desk. You take turns flicking your own, and you try to knock the other one off the edge. The desk has no walls, so a flick that misses can carry your own pen off instead.
On your turn you flick your own pen, once. Both pens slide until they stop, and then it is the other player's turn. There are no fouls. A flick that touches nothing still uses your turn.
You choose the direction, how hard (1 to 100), and where along the pen your finger catches it, from one end through the middle to the other end. There is nothing else to do: you cannot pin the pen down, and you cannot touch the other one.
A pen is off the desk when its centre crosses the edge. A pen with one end hanging in the air is still on. It is also in a lot of trouble.
If your flick sends your own pen off, you lose the round, even if the other pen went off as well. You cannot win a round by taking both pens over.
Catch a pen side-on near one end and it swings round, and it leaves slower, because part of the flick went into the turn. Push it along its own length and it slides dead straight wherever you caught it. A pen also has a clip down one side, so it drifts a little off the line you sent it on. The clip is drawn on the pen and it does the same thing every time. Nothing in the game is random.
After ten flicks in a round, every further flick brings all four edges in a little before it is played, until the desk is 45 percent of its starting width and height. If the new edge would leave a pen outside, the pen is moved back on. The shrink never knocks a pen out. Only a flick does.
A pen going off ends the round and the other player scores a knockout. The desk goes back to full size, both pens go back to their starting places, and the player who lost the round flicks first. The first to 3 knockouts wins the game. A game that reaches 300 flicks stops there: more knockouts wins, and level is a draw.
Their pen has stopped near the far edge, side-on to you. Yours is in the middle of the desk.
You aim straight at the middle of their barrel and choose your power. This is the whole decision. At full power your pen travels further than half the width of the desk, so if you miss, or only clip the end of their pen, yours keeps going and may be the one that leaves.
You hit it square. Their pen is shoved back and its centre goes over the edge. That is a knockout, and one point to you. The desk is reset to full size, both pens go back to where they started, and they flick first in the next round.
If their pen had stopped with its centre still on the desk, nothing would be scored. It would simply be their turn, with their pen on the brink and yours sitting next to it.
This is a playground game. You and whoever sat next to you each put a biro on the desk and took turns flicking, and the one whose pen stayed on had won.
Not every school played it this way. Some played to flip the other pen over, and some kept points across rounds. The rules above are knock-it-off-the-desk, which is what these tables play.
Biro Boxing is one of the games in the Arcade.