Rules of Shut-the-Box
The rules of the game are quite simple, and here I will exhaustivelyexplain them to the best of my ability.
As you probably know, the game involves two dice and a wooden boxconstructed with shutters or sliders that can be moved to revealor conceal each of the numerals from one to nine.
The player begins by rolling the two dice. The sum of the dicebecomes the target value for that particular round. For example,if the dice are as they look below, the target value for that roundis eight.
The player then proceeds to close any number of sliders such thatthe final sum of the sliders that have been shut during that particularround is exactly equal to the target. In the instance above, a player could close sliders 8; 1 & 7; 1,2 & 5; 1,3 & 4; 2 & 6; or 3& 5 since 8 = 8 = 1 + 7 = 1 + 2 + 5 = 1 + 3 + 4 = 2 + 6 = 3 + 5.
Before the player arrives at the target sum, the player has the optionto "take back" their last move. Continuing with our example, ifthe target is eight and the player starts by shutting the 2, and thendecides that shutting the 3 and 5 would be a better play, then theplayer is allowed to open the 2 and shut the 3 and 5, provided thatthe player has not yet shut the 6 (as 2 + 6 = 8, the target).
Once a slider is shut, it stays shut for the whole game. Shut-the-Boxdoes not involve subtraction from a slider total (though such a rulecould add another level of complexity to the game).
As the game reaches its completion, their exists another possiblesituation. For example, if a player successfully closes every numbersave 5 (that is, if 5 is the only number still open), the subsequentroll will be of a single die (die = singular of dice). The reasonfor this is straight-forward. If the total of open numbers is six orless, the probability of rolling that total increases if the playerrolls only one die. For instance, the odds of rolling a 5 on twodice are 1/9 or roughly 11% (meaning with two dice, you will roll 511% of the time). Using one die, the odds of rolling a 5 are 1/6 orroughly 16.6% (meaning you roll 5 16.6% of the time). In some versionsof the rules, players are allowed to decide if they would rather roll1 or 2 dice if the remaining total is 6 or less; however, it is always better to roll one die, so that is how I've implementedthe rules.
Play continues until all of the sliders are shut or until an impossible roll occurs. If all of the sliders are shut, the playercries out "ShutBox!" indicating that the player has accomplished the goal of the game, and in a multi-player situation, is likely to bethe winner. An impossible roll occurs if the sum of the dice cannotbe "shut out" by closing sliders. As mentioned before, the sum of the sliders shut must exactly equal the target sum. If thisis not possible given the remaining open numbers, then the game ends.
Again, if one rolls an eight, but only the five is left open, the gameis over and the score is 5. It would be impossible to close off the remaining open sliders to equal the target number in this case. Though the player in this case may be dissapointed that ShutBox wasnot accomplisher, 5 is a pretty good score. In the worst case scenario,a player could roll "snake eyes" (double ones, or sum of two) twicein a row. Since the two would have been closed on the first roll,on the second roll of 2, the game would end, leaving the player witha score of 1 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 43. This scenario happens1 of 1296 games or 0.077% of the time.
