A kind of vertical tic-tac-toe, with a plastic rack into which checkers can be slipped. Each player wants to get four checkers of their color in a row (horizontal, vertical, or diagonal) and block the other player from getting four in a row. Manufacturer Milton Bradley recommends it for ages seven to fourteen, but I think people much older or younger can enjoy it (unless they're the type who'll dump the checkers out of the rack rather than lose). There's now also an electronic hand-held version.

/-T-T-T-T-T-T-T-T-T-T-\
| | | | | | | | | | | | 
+=+=+=+=+=+=+=+=+=+=+=+
| | | | | | |X| | | | | 
+=+=+=+=+=+=+=+=+=+=+=+
|X| | | | |O|X| | | | | 
+=+=+=+=+=+=+=+=+=+=+=+
|O|X| | |O|X|X|O| | | | 
+=+=+=+=+=+=+=+=+=+=+=+
|O|O| |X|X|O|O|O|X| | | 
+=+=+=+=+=+=+=+=+=+=+=+

Connect Four is also a great notebook paper game for those too jaded or smart to keep playing tic-tac-toe or dots. The setup's pretty easy: draw a grid approximately with nine columns and six or so rows. In fact, without a board in front of me, I can't give you any exact dimensions. Generally you want more than seven columns and at least five rows. I usually go with 10x10. Milton Bradley's game (call it "regulation size") is six rows tall and seven columns wide.

But dimensions don't matter, all that matters is having fun and a mutual concept of gravity (usually, the edge nearest the bottom of the page).

---

And alfimp, do be careful with "wrong". Yes, I'd play with an actual board -- in fact, I'd love to build one -- but if I remember anything from my engineering and calculus classes, playing board games during lectures is very frowned upon. And outside of Jenga and that bottle caps game, Connect-4's about the noisiest (and for that matter, distractingly brightly coloured) game two could play.

Connect-4. So simple - a 6 row, 7 column grid with gravity, two players taking alternate turns at putting a red or yellow piece in until a row, column, or diagonal of one colour and of length four is constructed. In fact its simplicity, combined with the garishly bright red, yellow and blue colour scheme, and possibly also the 7-14 age tag, have caused many to consider it a game for kids. Not something for us real, adult people to condescend to play.

Well, it is my opinion that those people are wrong. Connect-4 is one of the most challenging, interesting and above all deep games ever invented. Like draughts/checkers, although it has been shown by computer that the yellow (first) player can always win, not even the best players in the world can guarantee a win. The possibilities for play are not endless, but they are so huge in number that the best that can be hoped for is to understand the openings, and to develop strategies for play. I'm going to talk about them now, so this is your official Spoiler Warning.

First, the openings. Yellow (who plays first) should always take the centre circle. If she doesn't, red can theoretically always win, and indeed generally does. Now it is generally accepted that red's response to this should not be to go on top of yellow, as yellow can then top the tower and get the crucial (4,3) circle, which can become an axis for diagonals and a horizontal. Personally I prefer to go just next to yellow - (5,1) or (3,1) in co-ordinate notation. After this, I don't believe there are any accepted rules for the progression, and many classic openings are possible, though I won't go into them here.

Strategy. Most people who play the game for an extended period tend to go theough a steady progression of more and more advanced strategies. First off, they think merely about trying to build loads of lines, in the hope one will be connect-4able. This soon yields to the first major strategy, or rather tactic (being local/small-scale) - using the "forced move". This is where you form two connect-3's simultaneously, with either both toppable to a connect-4 immediately, or with the "active site" (that is, the circle the taking of which would lead to a connect-4) of one being directly above the other. So your opponent will be forced to occupy one circle, allowing you to take the other and hence win. Cool! But as players become more experienced, they quickly learn to look out for this simple ploy, and such forced move tactics must become increasingly more intricate if your opponent is to suspect nothing until too late.

However, beyond a certain point of skill and foresight, these tactics become irrelevant as they are always seen and stopped. Here a new element of the game comes into play - Zugzwanging. Now that's a chess term, but it is just as applicable here, and it refers to a situation where the onus to move is a problem - i.e. when all legal moves for a player lead to them losing as a result of making that move. This happens in connect-4 because the board is finite. There are only 42 circles, and each column can take only 6 pieces before it is filled. So soon enough only a few moves will be allowed, and we frequently see the players being forced just to take turns filling up the columns until a connect-4 is formed (or the board is filled, which means a draw, though this is rare). So the trick is to make sure that it will be your piece that connects a four. This is tricky indeed, but you can get a decent chance by understanding one crucial consideration - parity. That is, evens and odds. Each column is 6 circles high - an even number. This means that it makes sense to consider each odd circle as "belonging" to yellow, and each even to red. The exact way this works is a bit complicated, but as a general rule of thumb yellow should aim to get odd active sites, and red even ones - although as it turns out, red also wins if he gets two odd ones.

So at this stage, we see a really interesting game having developed, where each player is constantly having to try to out think the other both tactically - trying to win by forced moves - and strategically - aiming to win by zugzwang - and indeed also trying to tactically achieve strategic ends. It all gets quite complicated, and very entertaining. So much from a clunky blue board and 42 coloured circles...

One final point. Some people think this is a game that can be as well played on pencil and paper as it can on a board. They are wrong. Pencil and paper is fine for practice, for figuring out strategies, or for when you don't have a proper board to hand - but nothing beats the sight, the feel, and above all the sound of letting your blindingly bright yellow circle chute down the column of an actual official moulded plastic Milton Bradley blue board, to hit those three appropriately coloured pieces previously put in place, bouncing with a delicious rattle and settling into yet another victory... pure bliss.

Connect Four is a pretty tame game on its own. One night at a local coffee joint, my friend luminuxious and I modified the game significantly, coming up with a new beast known only as:

KUNG FU CONNECT FOUR.

"Kung fu Connect Four?" you ask. "Kung fu Connect Four," I answer.

Rules

All standard Connect Four rules apply. The following rules are added in:

1. Each turn must be completed within one second.
2. Voluntary thought is not allowed, even if it fits within that time frame.
3. Each move must be accompanied by an appropriate sound effect... namely, one of the following:
   • A martial arts-style scream ("hiiii-YA!" "MEN!" "hoooo!" etc.)
   • A punch or kick sound effect ("pfsfsth!")
   • A vocabulary word from a random East Asian language, screamed as loudly as possible ("MING!" "KACHI!" "NGUYET!" etc.)
4. When the game is finished, the loser must leap from their seat, fall to the floor, and writhe in agony for a moment before getting back up and setting up the next game. The winner is allowed a mandatory period of dissing the loser.
5. In the end, everyone wins.

Copious amounts of caffeine or hallucinogenic drugs are recommended for the best gameplay. Also, a crowd of innocent bystanders helps immensely.