As a child, I have played many times with the cards to "war." All cards are dealt between two players and each player draws one at a time. The major card wins, and the two cards are taken by the lucky player. If you draw each equal card, "war" occurs, tie. A card is drawn again and the card with the highest value takes all the cards.
I rarely remember being able to finish any game. It became endless.
Now, I have made a simulation App of that game. And I have come to the conclusion that it is very important to shuffle or not the cards of the tricks made of each player, or just place them neatly under his club as they are won ...