Scores are entered after each round on a score pad with a column for each player. To total each column at the end of the playing session, you add up a player’s minus scores and his plus scores separately. Subtract the smaller sum from the larger and give the result the same sign (plus or minus) as the larger figure. For example, a player’s wins total minus 3210 points and his losses total plus 1530. You write down the difference, 1680, as a minus amount at the bottom of the column.
It is possible to keep a running score, adding and subtracting as you enter the score for each new round. If you prefer this method of scoring, add an extra column in which to enter the amount the winner receives for each round. It might become necessary to later check back on the accuracy of the scoring.
Now is when it becomes fun, or complicated, depending on how you look at it. It probably sounds more complicated then it really is, and it just adds more excitement to the game. It takes a bit of arithmetic on your part to figure out the end result of a session of International Rummikub but it is well worth it.
Example:
| Player #1 | Player #2 | Player #3 | Player #4 | |
| (a) Total Scores | -1200 | +7800 | -2320 | +16200 |
| (b) Addition Factor | +2320 | +2320 | +2320 | +2320 |
| (c) Primary Scores | +1120 | +10120 | 0 | +18520 |
| (d) Sum of Primary Scores | +23760 | +29760 | +29760 | +29760 |
| (e) Primary Scores X 4 | -4480 | +40480 | 0 | +74080 |
| (f) Final Scores | +25280 | -10720 | +29760 | -44320 |
The totals of each player’s columns, line (a) in the example above, will now contain both plus and minus scores, but they do not tell you exactly how much each player has won or lost. As you can see, Players 1 and 3 were winners and Player 2 and 4 lost, but do you know how much?
Our first step is to convert all scores into plus amounts, and to do this we add the same number, an Addition Factor, to each column, line (b) above. This number can actually be any random number, since it will be used equally in each player’s column, but the easiest way to pick the Addition Factor is change the sign of the largest minus number to plus as shown. In our example -2320 is the largest minus score, so we add 2320 to each player’s scores at line (b). This gives us each player’s Primary Score line (c).
Next we add all of the primary scores together, and write in the sum below each primary score as line (d). Now, multiply the primary score of each player by 4 and write down the product in each column as line (e). We then subtract line (e) from line (d) and we arrive at line (f), the final score of each player.
As you can clearly see, the winners, Players 1 and 3, now have plus scores. Player #1 has won 25820 points and Player #3 has won 29760 points. The losses of Player 2 and 4 are 10720 and 44320 points respectively. Their sum is equal to the sum of the winnings, which proves that our computations have been correct.
If you would like to save a little time and don’t mind remembering a short formula you can avoid some of the math involved. When you have arrived at the total scores of each player, simply switch the plus and minus sign of your score, multiply by 3 and add the result to the scores of the other players. For instance, Player 1 had -1200 as a total score in the example scoring. Using the shortcut formula, you simply change the minus sign to a plus (1200), multiply it by 3 (3600) and add the totals of the other three players (21680) to get the same final score, 25280.
When you have a game involving five players it works exactly the same way, except you add another column for the fifth player.