Board of Coastal Charts · field desk

Mapfold

One sheet, two routes, a quay at the far end of both. The checkpoints are brass pins driven into the board under the sheet, and the two routes have come unstuck from them. You have a bone folder and a small allowance of creases. Put them back together.

Crease. Pick a bearing, slide the crease, and choose the half that turns over. Folding reflects everything on that side of the line.
Cross. The sheet folds; the pins do not. Both routes have to end up running over every pin, and only the creases decide where they land.
Walk. When every pin is crossed, walk the road and then the ferry line to the quay. A clean crossing is worth more than a near miss.
Economise. The survey pays for crossings and for every crease you did not use. You may unfold and try again, free.

Arrow keys or A and D slide the crease, W and S turn the half over, J and K swing the bearing, Space creases the sheet, R unfolds the last one, H opens this card, M mutes, Escape holds.

House rules

How the folding works

Reflection. A crease is a straight line. Everything on the chosen side is reflected across it; the other side stays put.
Stacking. A flap always lands one paper thickness above whatever is already there, so later creases lift what earlier creases laid down.
Pins. A checkpoint is a brass pin in the board, not a mark on the paper. Paper moves, pins do not, so folding is the only way to bring a route over one.
Clean. A pin counts when both routes pass within a finger's width of it, and counts clean when they pass close and cross at a real angle.
Allowance. Each sheet allows one more crease than it strictly needs. Unfolding is free, so experiment.

Keys: ← → or A D slide the crease, W S turn the chosen half over, J K swing the bearing, Space or E creases, R unfolds the last crease, Enter walks once every crossing is made, H this card, M mute, Escape hold.

The desk is still

Held

Sheet one walked

Two routes, one quay

Sheet score 0 · survey 0