iDoku Solving Tips

iDoku is a variant of ordinary sudoku that appears in the 'i' newspaper.
iDoku puzzle

Rules

The aim of iDoku is to fill each row, column and 3x3 box in the puzzle such that 1-9 appear once only in each of them. In addition, there is a pink/red letter 'i' shape in the middle of the grid, matching the logo of the newspapering, covering nine cells, and crucially these too must contain 1-9 once only.

iDoku Solving Tips

The key to solving iDoku as opposed to ordinary sudoku is to remember that this extra region exists, and thus that there are 28 regions in the puzzle rather than the usual 27 of a standard 9 x 9 puzzle.

If you don't consider the central 'i' shape, then you won't be able to solve the majority of iDoku puzzles.

The central 'i' behaves the same as any other region in the puzzle, so if there is a '1' in the first cell of the 'i', then this means that none of the other eight cells can contain a '1'.

Once you get the hang of this rule and eliminating values that appear in the 'i', then you can continue to solve iDoku puzzles as you would a regular sudoku puzzle.

You'll never need to guess when solving an iDoku as logical rules can be used at all times to make progress, and you can use the same types of logic as you would when solving an ordinary sudoku puzzle.

If you have any questions about iDoku then please do post them below.

If you'd like to have a go at solving iDoku, then you can solve an iDoku Puzzle Online with our online sudoku player.

The video below outlines the rules of iDoku if you prefer a visual explanation:

Last update: October 2019
Date written: 19 Nov 2010

Category: sudoku | Keywords: idoku

Comments:

Havent tried idoku yet!
By: William - 15 Jul 2012 23:26:38

Where are the answers to the daily iduko please?
By: Ruth - 15 Jul 2015 12:41:25

You can find the daily solutions at: The I puzzles Solution Page
By: Clarity Media - 27 Jan 2017 12:57:49

Please send me a link to the solution got the iduko set on Thursday 6th April 2017.
By: Gordon Beastall - 08 Apr 2017 11:21:25

Hi Gordon, if you visit: The Solutions Page and scroll down to the bottom of the page, you can view solutions for 6th April 2017, assuming you do so within 10 days from the date of publication. Hope this helps!
By: Clarity Media - 08 Apr 2017 19:58:06

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