iKnockOut26.0

iKnockOut is a fun way for 1 to 4 students to learn addition and subtraction of numbers between 1 and 18. Play against the computer in one player mode. The game consists of a board with 18 numbers 1 through 18 with two spots per number to hold a colored marble. Marbles are placed on a number based on the roll of three dice. Placing a marble on a number with another color marble will knock the other marble out. A number with two marbles of the same color are captured and cannot be played on any more. Capture five numbers before your opponent to win the game. There are three play modes: Standard, Modified and Free Play.

STANDARD PLAY:
The values of the dice must be added or subtracted to equal an open number on the board. All dice must be used to place one or two marbles on the board. You cannot place three marbles and you cannot place your two marbles on the same number in a single turn. For example, if you rolled a 3, 6 and 5, on an empty board there are 10 possible moves. Some possible combinations for one marble are 3+6+5=14 or 6-3+5=8. Some possible combinations for two marbles are (6-5=1 and 3) or (5 and 3+6=9). I'll let the user figure out the other possible moves or tap HINTS to see other moves.

MODIFIED PLAY:
Place marbles based on the total sum of the dice. One to ten marbles may be placed. You are not limited to two marbles like standard play. For example, if you rolled a 3, 6 and 5, the sum is 14. You then add or subtract open numbers that total up to 14. Therefore you can place one marble on 14 or two marble on 11 and 3 (3+11=14) or two marbles on 15 and 1 (15-1=14) or three marbles on 1,2 and 11 (1+2+11=14) or four marbles of 2,3,4,5 (2+3+4+5=14). The HINT button will show combinations up to 3 marbles.

FREE PLAY:
In FREE Play there are no rules and no hints. Make up your own rules. There is no limit to the variation you can come up with for this game.

Version History Update for iOS26 26.0 10/07/2025 Update for iOS 17.0. Backward compatible to iOS 15.5. 17.0 12/19/2023 Update for iOS 16 16.0 05/15/2023 Update for iOS 13 and dark mode 13.0 04/14/2020 Update for new iOS.
Bug fix 12.0 11/09/2018 Update for iPhone X
Update for iOS 11 11.0.0 11/11/2017 Update for Swift 4
bug fix 10.0.3 09/25/2017 Updated instructions 10.0.2 05/29/2017 Bug Fix 10.0.1 05/26/2017 Update for iOS10 and Swift 10.0.0 05/22/2017 Fixed two player with red and green colors.
Reduced the number zero combinations on roll. 7.0.3 06/01/2014 Allow students to select their color
Random person starts game 7.0.2 05/27/2014 Update icons
Fix dice placement 7.0.1 11/20/2013 Updated for iOS7.0 7.0 09/17/2013 Fix background to fit on 4 inch screen 1.4 09/20/2012 - added toggle for challenge on/off
- added Strict error checking when not in Challenge mode
- Limit modified play to 10 marbles (simplifies error checking)
- Updated instructions
- Prevent 1 player in free play 1.3 09/06/2012 1.2 08/15/2012