Tap the game to open it fullscreen. On a computer, Esc exits; on a phone, use the ✕ button.

How to play

A marker moves back and forth along the bar. Tap (or press the space bar) when it crosses the golden zone. Each good strike lengthens the blade, speeds up the marker and narrows the zone. Eight good strikes forge the sword; three mistakes crack the blade.

The story behind it

About 170 swords from the 9th to 11th centuries bear the name VLFBERHT, and some have exceptional steel. The rhythm forging is a simplification by the game. Read the story in The Ulfberht swords: the name engraved on Viking blades and the steel mystery.