Slant Diagonals Unblocked

Slant Diagonals sounds almost too plain to be a puzzle: every square needs a single diagonal line, either / or . Then two rules arrive. Circled numbers sitting on grid corners tell you how many lines must touch each point, and the lines must never join up into a closed loop, no matter how large. Balancing local counts against that global no-loop rule is what keeps this puzzle interesting long after you learn it. The puzzle is Slant, part of Simon Tatham’s collection, and it is playable unblocked on any browser.

Slashes, Corners and the No-Loop Rule

A backslash links a square’s upper-left and lower-right corners, while a forward slash links its upper-right and lower-left. A finished grid has no empty squares.

Clues live on the points where squares meet. An inner point is shared by four squares, and its number says how many of their diagonals reach it. So a 4 sits where an X meets, while a 1 means three of the four lines lean away.

The loop rule is the one that bites. If your diagonals ever enclose an area, the board is wrong. The game highlights loops and impossible clues in a warning color, which helps you catch an error before it spreads.

Left-click places a , right-click places a /, and further clicks swap the direction and then blank the square. A solved grid flashes.

Slant Diagonals controls

To do this	Keyboard	Mouse	Touch
Place a \ line (repeat to cycle)	Arrows to move, then Enter	Left-click a square	Tap a square while Tap is set to "\ first"
Place a / line (repeat to cycle)	Space	Right-click a square	Press and hold, or switch Tap to "/ first"
Set a direction or clear the square	Type / or \, or Backspace to empty	—	—
New puzzle, undo, redo	N, U, R	Buttons above the grid	Buttons above the grid

Things I Wish I Had Known Earlier

Edges are generous. Border clues have just two squares around them, and a corner clue has one. A 0 or 2 on the border fixes both lines right away.

Every line affects two clues. A diagonal touches two opposite corners of its square. After you place one, check both ends. Often a clue becomes full, and then the rest of its squares must lean away from it.

Three sides of a diamond is a warning sign. If three squares already outline most of a tiny diamond, the last one has to tilt the opposite way, or you close a loop.

A 0 never sits in the middle. All four lines leaning away from an inner point would make a diamond, which is a loop. If you see a 0, it is on the edge.

Trace long chains. Loops don’t have to be small. Before placing a line that joins two existing chains, follow them to see whether they already connect somewhere else.

If you find the default mouse buttons backwards, Preferences can swap which button gives which slant.

Grid Sizes and Related Puzzles

The presets include 5x5, 8x8 and 12x10 grids, each at Easy or Hard, plus custom sizes. A small Easy grid takes a few minutes, while a 12x10 Hard board is a proper sit-down session.

The no-loop idea shows up in other logic games too. Try Loopy Loop Puzzle, where the aim is the opposite: make one big loop. Or browse the full set of puzzle games on FreezeNova.