If you are a fan of grid logic puzzles like Suduko or love building straights in card games, you will love Straights (or Str8ts) logic puzzles. Like so many puzzles of this type, Straights (Str8ts) logic puzzles have just a few deceptively simple rules.
Straights or Str8s is a wonderfully clever logic puzzle that blends the number placement challenges of Sudoku with the fluid sequence-building of traditional card games. If you enjoy placing numbers, hunting down clues, and watching a grid slowly click into place, you’re going to love this game.
The Str8s or Straights grid is made up of white and black cells. The black cells break up the rows and columns into sections which are known as compartments. Examples of compartments are shown in the example below. Note how a compartment is defined either by the edge of th grid or a shaded cell:
Rules of Str8s / Straights Grid Logic Puzzles
The goal of Str8s is simple: fill the white cells on the grid with digits to form contiguous sets of sequential numbers, which are known as straights, across every group of cells known as compartments. While it shares some visual traits with Sudoku, its unique mechanics demand a fresh tactical mindset.
The Basic Rules
- Number Range: A standard 9×9 grid uses digits 1 up to 9. Smaller variants (like 6×6) use 1 through 6.
- No Repeats in Rows or Columns: Just like Sudoku, a digit cannot repeat within any single row or column across the entire board, regardless of cell colour.
- Compartments & Straights: Black cells break up the rows and columns into smaller white “compartments.” Every continuous group of white cells must contain a straight (a sequence of consecutive numbers, such as 3, 4, 5, 6). However, super-importantly, the order Doesn’t Matter. The digits within a compartment do not need to be in numerical order. For example the set 5, 3, 4 is a valid straight for a 3-cell compartment because it forms the consecutive sequence 3-4-5.
- Black Cells as Blockers: Black cells interrupt compartments and block digits from appearing in that row or column. They take two forms:
- Clue Black Cells: A black cell containing a printed number prevents that specific digit from being placed anywhere else in that row or column. However, these printed numbers are not part of any straight.
- Blank Black Cells: Simply act as compartment dividers.
Useful tips for solving Straights Grid Logic Puzzles
TIp 1: Remember that the consecutive number rule applies only to compartments not to a row or column (unless it is a row/column which doesn’t contain any black cells). Notice how the compartments below don’t ‘connect’ or relate to each other.
Tip 2: The shaded cells mean that not every number will appear in that row or column – this means that, for example, a compartment containing 5 cells in a 9 cell grid could contain 1,2,3,4,5 or 2,3,4,5,6 or 3,4,5,6,7 or 4,5,6,7,8 or 5,6,7,8,9! Therefore look for complete rows or columns as these may provide clues as to where certain numbers may go:
Rules in Action: What Works and What Doesn’t
Valid Compartment Examples:
Note how the different compartments contain all consecutive numbers – but not necessarily in order.
Invalid Compartment Examples:
- The numbers must always be a straight and not contain any gaps. 2,4,3 is value whereas 1,4,3 isn’t as it’s missing the number 2
Grid Restriction Example:
- If a black cell has a printed 4, you cannot place a 4 in any white cell along that entire row or column. This is a really useful rule to remember as it helps to restrict the options when placing numbers.
Now that you know how the board operates, let’s step through a live puzzle together and break down the exact logical deductions you’ll use to solve it!
STR8Ts or Straights Grid Puzzle Walkthrough
This is the grid we are going to use for this walk through. The first thing to note is that it is a 9×9 grid, therefore cells can only contain numbers between 1 & 9.
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How to Solve Straights Logic Puzzles Walkthrough
Step 1
Small compartments and areas which are already completed represent a good place to start. Not how the column compartment highlighted already contains a 2? Theoretically the remaining cell could be a 1 or a 3. However, because there is already a 3 in this column (remember the handy ‘no number can be repeated in any row or column rule 🙂 ), this means that the remaining cell in this compartment can only be a 1.
Step 2
We can do the same in this compartment. The shaded black cell is telling us there can not be the number 1 in this row. Two cells are shaded which means there are only 8 available cells. Given we already have a 6 & 4 in this section, we know the remaining three numbers must be 2,5 and 3. Looking through the completed cells in the relevant columns, we can see there is only one place the 3 can be situated, which means there is only one place the 2 can go – which in turn means the 5 has to be placed in the remaining cell.
Step 3
Looking now at the remaining cell, this has to be an 8 because 6 has already been used in the other compartment.
Step 4
We can now complete the rest of the compartments in this row. Because we now have 5,6 and 8 in the top compartment, we know that the remaining cell must be 7 (the shaded clue cell would have helped here too as we know the number 4 cannot appear in this column, therefore even if we didn’t have the 8 placed, this compartment could not have been a straight containing 4).
We can also finish the bottom compartment.
Step 5
Looking at this compartment, we already had 6 and 3 placed, therefore we know that to make this compartment contain a consecutive sequence of numbers, it must contain a 5 (which we added earlier) and a 4.
So we know it will contain 3,4,5,6 – however the fifth cell could be either a 2 which makes the straight 2,3,4,5,6 OR a 7, making this 3,4,5,6,7.
Looking at the numbers already completed, we know that the 4 can only go in one place and the remaining cell cannot contain a 2, which means the remaining number is 7.
Step 6
As more cells get completed, don’t forget to take an overview of the grid with the new numbers as this is likely to have opened up new opportunities and eliminated unwanted options. All the cells with numbers in red have been completed just by looking at what numbers are needed to create a straight – and looking to see where they can’t be placed because of numbers already in that column/row.
Step 7
There is never any need to guess. The answers will reveal themselves. We can see here that we know the compartment row must contain a 9, however the compartment column that intersects it cannot contain a 9 as there are 5 available cells including a 4 and 8, so it can only contain the 5 numbers 4,5,6,7,8.
Continue working through the grid, looking at clues, understanding what numbers are needed and what can’t be placed and you’ll have the grid complete 🙂
The key things to remember when completing Straights Logic puzzle is to remember that compartments must contain a ‘straight’ of consecutive numbers, but they needn’t be in order and that compartments are independent of each other meaning a row or column needn’t contain all numbers in the grid size. Combine this with the super-handy rule that no number can be repeated in a column or row and this is a very engaging puzzle to complete 🙂
