I have been working on a simulation in which two bots play the card game War.
Rules of War
If you aren't already aware of the rules, basically the premise of the game is to get all of the cards. You split one deck evenly (though I just gave them both one 53 card decks to start out with), and every round you both place a card from your deck (deck has to be face down). Whichever card's bigger gets to keep its card and the opponent's card.
If both cards are the same, you go into a War. You both place down another card, rinse and repeat until someone has the bigger card, then the winner gets all of the placed cards in that round. Every used card goes into a discard pile faced up. When your deck runs out, you shuffle the discard pile and use that. The winner is decided when only one person has all the cards.
Basically, the first deck always wins for some reason, and with more cards than what is possible (both start with 53, 53*2 is 106, it's impossible to have 109 cards at the end) and I can't figure out why.