The beginner's guide to flow

Everyone's first dozen flow boards go the same way: connect the pairs that look easy, run out of room, clear, retry. That's fine — it's fun — but the game gets far better when you stop guessing and start reading. This guide teaches the four habits that do it.

Habit 1: corners first

A corner square touches only two other squares. Whatever pipe covers it must enter through one neighbour and leave through the other (or start there, if a dot sits in the corner). That means corners are nearly decided before you draw anything. Scan all four corners before your first drag: very often one of them can only be reached by one color, and that single deduction anchors a whole side of the board.

Habit 2: hug the walls

Watch a strong player and you'll see their pipes trace the border constantly. It isn't superstition: a pipe running along the wall walls nothing off, because everything it passes stays reachable from the open side. A pipe that cuts through the middle of open space divides the board in two — and one of those halves frequently ends up unreachable. When two routes look equal, take the one closer to the outside.

Habit 3: never strand a square

The fill-every-square rule means an empty square that no pipe can reach anymore is an instant, silent failure. Train the glance: every time you commit a pipe, look at the pockets it creates and ask, "can some pipe still get in there — and out?" A pocket with one entrance can be filled only by a pipe that ends inside it (i.e. a dot lives there). No dot, one entrance: your route is already wrong, even though the game hasn't complained.

Habit 4: expect detours

Two dots sitting side by side almost never connect directly. Why? Because the board's squares must all be used, and the designer (well, the generator) placed those dots so their pipe soaks up territory. When a connection looks trivially short, the real question is "which empty region does this pipe actually need to sweep through?" Deliberately routing the long way — through the area nothing else can cover — is the single most flow-specific skill there is.

A worked opening

On a fresh board, run this order:

1 Corners: who covers each? Draw any forced corner runs.

2 Border: extend dots that sit on the edge along the wall in the direction that stays forced.

3 Central pairs last, routed through whatever open area remains — they're the sponges that soak up the middle.

4 Every few pipes, do the stranded-square glance. Cheaper to fix now than after four more pipes.

Mistakes are free

Two mechanical notes that change how boldly you can play: dragging backwards along your own pipe rewinds it, and drawing through a wrong pipe cuts it — the board never enters an illegal state. So sketch! Draw a candidate route, look at what it strands, and cut it back. On easy and medium boards, sketching plus the four habits is a complete method. When you're ready for harder boards, the techniques guide names the deeper deductions.