A game of snake. Move the red counter to eat the green counter. The more you eat the longer your snake gets. Touch the sides or your own body and the game is over.
Once your snake eats enough and fills the grid there is nowhere else to put food the game is over. Therefore, the highest score you can get in this game is 16.
A fer-de-lance is a snake from South America. A joke is always better when you explain it :)