Each player takes a turn rolling the die. He/She doubles the number on the die and then places a token or marker on that number on the gameboard. If another player has a token on the board you can BUMP him/her off. But if a player has two tokens on a number, then he has won that number. The game ends when the entire board is full. The winner is the player that has won the most numbers.
You can download the fall-themed gameboard here. (4+4, 5+5, etc.)
Now knowing that LD would want to play as well I made him his own gameboard. This version uses the same die (with the numbers 4 through 9), but instead he multiplies by 8. (4x8, 5x8, 6x8, 7x8, 8x8, 9x8)
So if he rolls a 5 he multiplies that by 8 and has to cover the number 40 on his gameboard. The same rules apply -- you can bump a player off if they have one token covering the number, but once a player has two tokens on a number he has claimed/won that number and cannot be bumped off.
You can download the Bump 8s Multiplication Gameboard here.