Play Skunk Online

What Is Skunk?

Skunk is a push-your-luck dice game built around a single question asked over and over: do you stay standing for one more roll, or sit down and keep what you have? It is played in five rounds named after the letters of its own title, S, K, U, N and K, and unlike almost every other dice game the rolls are shared. One pair of dice is thrown for the whole table, and everybody still on their feet scores from it. A 1 on either die ends the round and wipes the round score of everyone still standing. Two 1s wipe their entire game total.

The shared roll is what makes Skunk feel different from its one-die cousin Pig. In Pig, your risk is private; in Skunk, the whole room holds its breath together, and the player who sits down a roll too early has to watch everyone else collect. That is also why it became a classroom favorite: thirty students can play at once, every one of them making a real decision on every roll, and the mathematics of when to sit is simple enough to work out on the board afterwards.

A Short History of Skunk

The name comes from a boxed game. In 1953 W. H. Schaper of Minneapolis, the company behind Cootie, released Skunk, a two-dice game in which the 1 on each die was replaced by a picture of a skunk. Players took individual turns, rolled as often as they liked, and raced to 100 points; a skunk ended the turn and cost chips, and two skunks cost more. That version, with its poker chips and score pad, is the one collectors find on auction sites today.

The version most people now know is the classroom one, and it owes its spread to a single article. In April 1994 Dan Brutlag published “Choice and Chance in Life: The Game of SKUNK” in the very first issue of Mathematics Teaching in the Middle School (Vol. 1, No. 1, pp. 28–33), the journal of the National Council of Teachers of Mathematics. Brutlag described Skunk as “a variation on a dice game also known as ‘pig’ or ‘hold’em’” and laid out the five-column S-K-U-N-K score sheet, the whole-class stand-or-sit procedure, and the single-1 and double-1 penalties used on this page. The article was later adapted into an NCTM Illuminations lesson, complete with a projected dice simulator so a teacher could roll for the whole class, and from there it spread into probability units, math circles and family game nights.

Brutlag’s point was never really the game. It was that Skunk “presents students with an experience that clearly involves both choice and chance,” and that thinking about it afterwards, comparing strategies and estimating how often a 1 shows up, is where the learning happens. Thirty years on, the article is still the standard reference for the rules.

Skunk Rules

Equipment

• Two six-sided dice, rolled by one person for the whole table
• A score sheet per player with five columns headed S, K, U, N, K and a Total box
• Two or more players; the game works just as well for a full classroom as for a pair

Object

Finish the five rounds with the highest total. Each round’s banked score is added to your running total; a wiped round scores zero, and double 1s send a standing player’s total back to zero.

How a Round Works

1. Everyone stands. At the start of each round every player is standing, and nobody may sit before the first roll.
2. Roll two dice. One roll serves the whole table.
3. Score or suffer. If neither die shows a 1, every standing player adds the two-dice total to their round score. If exactly one die shows a 1, every standing player’s round score becomes zero and the round is over. If both dice show 1s, every standing player’s round score and game total become zero and the round is over.
4. Stand or sit. Before the next roll, each standing player decides. Sitting banks the round score into the total; that player takes no further part in the round and cannot stand up again. Standing means taking the next roll, for better or worse.
5. Round ends when a 1 appears or when everyone has sat down. Write the round score in the column, move to the next letter.
6. After the final K, total the five columns. Highest total wins.

Scoring Table

Worked Examples

• A clean round. The rolls are 4-6, 3-5, 2-6. You stand through all three and your round score reads 10, then 18, then 26. You sit. The next roll is 1-3: your opponent, still standing on 26, loses the lot and you bank 26.
• Sitting too early. You sit after 6-5 with 11. The table then rolls 4-4, 6-3 and 5-5 before a 1 finally appears; the player who sat one roll before the 1 banked 37.
• The double-1 catastrophe. In round N you have 61 banked and stand for a first roll. It comes up 1-1. Your round score was zero anyway, but your total is now zero too. This is why players with a big lead sit down after a single modest roll in the last rounds.
• A first-roll skunk. Round U opens with 1-5. Nobody has had a chance to sit; everyone scores zero for U and the game moves on to N. The dice do not owe you a good start.
• Last-round arithmetic. Going into the final K you trail 58 to 70. Your opponent sits after one roll of 9, finishing on 79. You now need a round score of 22 or more, so you keep standing at 20 even though the odds of surviving one more roll are only 25 in 36; sitting on 20 loses for certain.

The Odds Behind Skunk

One roll of two dice

Of the 36 equally likely results of two dice, 25 contain no 1 at all, 10 contain exactly one 1, and one is double 1s.

• P(at least one 1) = 11/36 ≈ 30.6%. That is the chance any given roll ends the round.
• P(double 1s) = 1/36 ≈ 2.8%. The chance a given roll wipes your total.
• Average total of a safe roll = 8. The 25 safe combinations sum to 200, so a roll that does not skunk you is worth 8 on average, not 7.

Surviving several rolls

The chance of seeing no 1 in k consecutive rolls is (25/36)^k:

The third column is 8k × (25/36)^k: the value of a fixed plan to stand for exactly k rolls and then sit. It peaks at three rolls, at about 8 points per round or 40 points per game, and that ignores the extra cost of double 1s. Brutlag’s own back-of-the-envelope figure was more optimistic; his rating chart assumed a 1 “happens on about the third dice roll” and a “roll twice then stop” plan collecting about 16 points in four rounds out of five, for around 64. The expected number of rolls before a 1 appears is 36/11 ≈ 3.3, so the third roll is indeed where the trouble usually starts, but the probability of surviving two rolls is under a half, which is why the honest average for a two-roll plan is closer to 8 than 16.

The value of standing

Suppose your round score is r and your banked total is T. One more roll has three outcomes: with probability 25/36 you gain 8 on average, with probability 10/36 you lose r, and with probability 1/36 you lose r + T. The expected change is:

(25/36) × 8 − (10/36) × r − (1/36) × (r + T) = 5.56 − (11r + T) / 36

Setting that to zero gives the break-even round score: r = (200 − T) / 11.

• With nothing banked (T = 0), stand while r is below about 18.
• With 50 banked, the break-even falls to about 14.
• With 100 banked, it is about 9.

So the right moment to sit moves earlier as the game goes on and your total grows. A player who stands “until 20 every round” is playing slightly too loose in round S and much too loose in round K.

Skunk Strategy

1. Take the first two rolls

Nobody may sit before the first roll, and with a round score of 8 or so after it, the second roll is worth about +3 on average. Unless you have a large total to protect, standing for two rolls is almost always right.

2. Sit around 15 to 18 early in the game

The break-even round score with an empty total is 18. Because Skunk is won by beating an opponent rather than by maximizing your average, sitting a little before break-even, at 15 or so, keeps your variance down without giving away much expected value.

3. Lower your target as your total grows

Every 11 points in your bank lowers the break-even by one. At 55 points banked, sit at 13; at 88, sit at 10. The double-1 rule is rare but it is the only way to lose a whole game in one roll, and the more you have, the more it costs.

4. Watch what your opponent does

Rolls are shared, so the moment your opponent sits, you know exactly what you must beat this round. If they sit on 9 and you are on 9 too, one more safe roll puts you ahead with 69% probability; a 1 leaves you level. That trade is worth taking when you are behind and refusing when you are ahead.

5. Play the last round backwards

In the final K, expected value stops mattering and only the finishing line counts. If you are ahead after your opponent sits, sit immediately. If you are behind, keep standing until your total would pass theirs, however unlikely the dice make that look; a certain loss is worse than a probable one.

6. Do not chase a wipe

A skunk in round S costs you a few expected points, not the game. Trying to “win it back” by standing to 30 in round K only raises the chance of a second wipe. Reset your target to the scoreboard, not to the story so far.

7. Respect the lead in rounds N and K

A 20-point lead with two rounds left is large. Sit after the first roll of each round if you can, bank 8 or so, and make your opponent take the risks. The 11-in-36 wipe rate does the rest.

Common Mistakes

• Standing to a fixed number every round. The right target depends on your total and the round; 20 in round S is reasonable, 20 in round K with 80 banked is reckless.
• Sitting before the second roll with nothing banked. Round scores of 5 to 8 are not worth protecting when a second roll adds 8 on average.
• Forgetting that double 1s wipe the total. Players who treat 1-1 as “just another skunk” stand far too long late in the game.
• Ignoring the opponent’s decision. Once they sit you know the number to beat; play to it.
• Believing a 1 is due. Each roll is an independent 30.6% chance. Five safe rolls in a row make the sixth no more dangerous.

Variants and House Rules

• Schaper’s 1953 Skunk. Individual turns, roll as long as you like, first to 100 wins. A skunk on one die ends the turn and costs a chip; two skunks cost more. This is closer to Pig with two dice than to the classroom game.
• Double 1s only wipe the round. A gentler rule for younger players that removes the total-wipe. It makes standing late in the game much safer, so break-even scores stay near 18 throughout.
• Doubles score double. Some tables award twice the total for any double other than 1-1, which raises the average safe roll and nudges the break-even up.
• Individual dice. Each player rolls for themselves in turn, as in Pig. The stand-or-sit decision becomes roll-or-hold, and the “watch your opponent” element disappears.
• More letters. Longer games spell longer words; the rules do not change, but a good total scales with the number of rounds.
• Whole-class play. Brutlag’s original setup: everybody stands, the teacher rolls, students sit by sitting down. Instead of a single winner, players try to beat their own previous total.

If you enjoy the stand-or-sit decision, Farkle and Ten Thousand add scoring combinations to the same push-your-luck core, Sevens Out is another two-dice game where one particular roll ends the turn, and Zombie Dice turns the 1s into shotgun blasts.

Glossary

• Round score: Points accumulated in the current column; lost to any 1 while you are standing.
• Total: Points banked from finished rounds; lost only to double 1s while you are standing.
• Standing: Taking part in the next roll.
• Sitting: Banking the round score and taking no further part in the round.
• Skunk (verb): To lose the round score to a 1.
• Double skunk: Double 1s, which also wipe the total.
• Break-even score: The round score at which one more roll has zero expected value: (200 − total) / 11.
• Shared roll: A single roll of the dice that every standing player scores from.

Play Skunk Online on Dice.now

The game at the top of this page is the classroom version of Skunk, you against the computer, over the five rounds S, K, U, N and K. Both players start each round standing. Press Stand & Roll to throw the shared pair of dice: every standing player adds the total to their round score. After any roll you may press Sit to bank your round score; the button shows exactly how much you would bank, and it is unavailable before the first roll of a round, as in the original rules. A single 1 (shown in red) wipes the round score of everyone still standing and ends the round; double 1s also wipe their totals. The score sheet fills in as you go, with ✗ marking a round lost to a 1 and ✗✗ a round lost to double 1s, and the game log records every roll and every decision.

The computer decides before each roll, in the open. It sits at 15 in an even game, stands longer when it is behind, sits earlier when it has a lead or a large total to protect, and in the final round keeps standing until it is ahead once you have sat. It never sees the dice before you do. When all five rounds are complete the higher total wins; your total is submitted to the leaderboard and your best total and win record are kept on your device only.

Rolls use your browser’s cryptographic random number generator, so 1s arrive exactly as often as the arithmetic above says they should. Stand up and roll.