About Pairs Duel
Pairs Duel is the memory card game for two. Twenty cards are laid face down, hiding ten pairs of symbols. Players take turns to turn over two. The contest is as much about what you remember from your opponent's turns as your own.
How a match works
The symbols are simple shapes: a star, a circle, a triangle, a heart, a sun, an umbrella and so on. On your turn, tap one card, then another. If they match, both take your colour, you score a pair and you go again. If they do not, they stay visible for a second and then flip back, and it is the other player's turn.
When all ten pairs are found, whoever has more wins. With ten pairs, a five-all draw is possible.
How to win
Watch your opponent's turns as closely as your own. Every card they turn over is information for you, and you get it for free. Most pairs are won by remembering something the other player revealed.
Start each turn with a card you have not seen. If it matches one you remember, take the pair. If it does not, you now face a choice for your second card.
Choose the second card carefully. If you have no match, turning over another unknown card shows your opponent two new cards. Turning over one that both of you have already seen gives away nothing. Late in the game, that defensive play matters.
Remember positions by row and column. "Star, top row, second along" is easier to hold than a picture of the board.
Use your run. When you find a pair you go again, so a good memory can take three or four pairs in one turn.
Do not rush. There is no clock.
It is fair between ages, since children are often better at it than adults. For a calm contest, few two-player HTML5 games are as evenly matched.