Barbed Wire

Used since the mid-19th century on Earth, Barbed Wire and it's more threatening cousin, Razor Wire, is still a staple of basic defense on Mars. The cheaper barbed wire consists of evenly spaced spurs or barbs on a reinforced wire, while razor wire (barbed wire II) is stamped razors or burrs mounted to reinforced wire.

Both forms are easy to assemble and construct, even by unskilled labors. Neither are intended to completely stop an assailant, however they do slow the attackers progress, hopefully giving the structure's Security measures to turn on the attacker and drive them back.