# Duel of Four Knights

Four knights are preparing to duel. Each has a different weapon, and will start with it sheathed in his own corner of the square 10 by 10 meter chamber. Each knight moves 5 meters per second.

The Blue Knight has a straight sword that allows him to move twice as fast as the other combatants.

The Red Knight has a curved blade that can hit two knights at a time, provided that they are within 1 meter of each other.

The Black Knight has a wavy-shaped sword that kills anyone that touches its tip.

The Green Knight has a corkscrew-shaped sword that makes himself invisible while it is sheathed.

Who will lose this battle?

This feels like a trick more than a puzzle, if the following is the intended answer: perhaps

the black knight will lose

because

you can't extract a wavy sword from a similarly-shaped sheath.

But

perhaps the sheath is actually (e.g.) wedge-shaped and the sword goes in and out of it easily. (A real sheath for a wavy-shaped sword would be designed that way.)

• You are correct! This was a rather simple puzzle, and you got it real quick! May 8, 2019 at 1:25
• And there's no guarantee that they need the sword to win. May 9, 2019 at 18:04
• Hard to see how they have a real chance without it. May 9, 2019 at 18:06
• But they can block even with the sword sheathed, right? And perhaps parrying a blow will unsheathe the sword.. Jul 8, 2019 at 17:45
• How would it do that? The problem is that it physically can't slide out of its sheath. Jul 8, 2019 at 18:57