There are 5 piles of coins, one with 1 coin, one with 2 coins, etc.

1 2 3 4 5

You can take as many coins as you want during your turn, but only from one pile. ie you could take 3 coins from pile 4, 2 coins from pile 2, 1 coin from pile 5, etc.

Whoever takes the last coin loses.

Here’s a quick example game:
12345
12245
12234
12034
12030
11030
11010
10010
00010
00000 (loss)

If you go first, what move can you make to ensure that you win? I know the answer (spent the last hour working it out), but let’s see if you guys can figure it out!

Look down at the pile, look back at your opponent, rear back and smash them in the face, then take all the coins. Just before you leave, flip one up in the air so that it lands right on the bruised forehead of your beaten opponent. Lastly, say something badass like “Keep the change,” or “A penny for your thoughts,” then, leave the room; preferably to some sort of music.

Originally posted by Merlin Look down at the pile, look back at your opponent, rear back and smash them in the face, then take all the coins. Just before you leave, flip one up in the air so that it lands right on the bruised forehead of your beaten opponent. Lastly, say something badass like “Keep the change,” or “A penny for your thoughts,” then, leave the room; preferably to some sort of music.

There’s a simple enough algorithm to solve the problem, but I definately don’t feel like working through all of the cases to get the answer. I don’t have a nice solution, but from the answers people have given, and because at least one person has to take an even number of pieces for the first player to win, I’m guessing that it has something to do with eliminating all of the unpaired options first.

That is, if you want to win by following the rules.