This is how you learn the Time War
(Published on 26. February 2025, 04:51 by pdyxs)
This is the first of two puzzles based on the novel 'This is how you lose the time war', which is one of my favourites of the last few years. This puzzle will help acclimatise you to the ruleset, and be ready for the full 9x9 puzzle: This is how you live the Time War.
Rules
Sudoku: Fill the grid with the digits 1-6, so that each digit occurs exactly once in every row, every column and every 3x2 box.
Space-Time: Each row of the grid represents a slice of time, with the top row as the earliest and the bottom row as the latest. Each column of the grid represents a different location in space.
Timelines: Two Time Agents, Blue (2) and Red (5), are jumping forwards and backwards through space-time to help their side win the time war. The marked columns each represent an agent's timeline - each digit in the column shows the agent's age when they appear in that row. The rows below the grid can be used to keep track of each agent's age in each column, and are not a part of the solution.
Time Jumps: When jumping from one cell to the next (ie. when their age increases by 1), a Time Agent may travel as much as they like in time, but only up to 2 columns in space. For example, if Blue at age 3 is in column 2, their digit must appear in columns 1, 3 or 4 in the row where they are age 4.
Controlling cells: When the first Time Agent appears in a column, they take control of the cell they land in and all cells below them. Another Time Agent appearing later (ie. further down) in the column will take control, starting at the time that they arrive, if and only if they are older than the original Time Agent. For example: in a column that reads 142356, where Blue (2) has age 3 and Red (5) has age 4, the 2 and 3 would be Blue and the 5 and 6 would be Red.
Winning locations: For each column, take the sum of the cells controlled by each Time Agent - the Time Agent with the highest sum wins the location. Clues below the grid denote the winning sum (or the tied sum, in a tie).
Losing the Time War: The Time Agent who wins the most locations wins the war. No-one can win the war.
4x4 Example Puzzle
The Puzzle
Solution code: The squares that Blue controls in rows 3 and 4 (row 3, then row 4)
Comments
on 27. February 2025, 17:11 by spectria.limina
I misunderstood the rules, which led to a very messy and confused first solve.
Once I realised the mistake I'd made, I went back and did it from scratch and it flowed easily. Very nice puzzle, and fantastic implementation of a very tricky concept in Sudoku! I love the flavour, and it makes me sad that Red and Blue will never meet.
on 27. February 2025, 10:03 by pdyxs
Thanks for the lovely comments qoala, etoler, gfoot and brewring!
on 27. February 2025, 10:02 by pdyxs
Adding link to the next puzzle
on 27. February 2025, 07:54 by qoala
Loved this puzzle. I'll need to wait until tomorrow to solve the next one. Wait. Time travel. See you then!
on 27. February 2025, 06:35 by etoler
If you haven't solved this one yet, you're probably not solving the 9x9. If you HAVE solved this one, you won't be able to resist the 9x9.
on 26. February 2025, 14:58 by gfoot
Fun but very challenging to get your head around - until you figure out the consequences of the rules, it is quite daunting - looking forward to the next one for sure so I can put my learnings to the test!
on 26. February 2025, 12:21 by brewring
Absolutely loved this idea. I didn't look at the example so it took me a while to get the initial breakthrough but then it was fantastic. (Slight spiler warning: Absolutely love that the war ended in not only tie for locations but also the total controlled points)
