- "Their blades are more scythe than sword... the better to cull the infantry ranks without breaking stride."
- ―Ser Jorah Mormont
The arakh is the standard weapon used by Dothraki warriors. It has a crescent moon-shaped, curved blade about two and a half feet long and a thick handle almost the same length, making it half-sword and half-scythe. Although unable to penetrate armor, the arakh gives the wielder tremendous maneuverability of wrists.
Jorah Mormont notes that while the sweeping blade is effective and indeed necessary for a warrior on horseback, the arakh pales in comparison to the Westerosi double-edged sword for battling without a mount or at penetrating armor.
In the books
The weapon overall is an original invention of George R.R. Martin, but does bear some similarity to ancient "sickle-swords" such as the khopesh, the orak, the makraka, and the falx. Martin's description of arakhs in the books (A Game of Thrones, chapter Daenerys II) is: "...in the blink of an eye the arakhs were out, long razor-sharp blades, half sword and half scythe."
Martin's conception of arakhs, however, actually differs from the arakhs produced for the TV series. When Martin described arakhs as "half-sword and half-scythe", he meant a curved blade similar to a scimitar. The TV series took his description literally, making a blade that starts out as a straight sword before turning into a circular, curved scythe-shape halfway through.
Arakhs are best used in open spaces. In closed quarters, the arakh's length would become a serious drawback to its wielder, as happened to Hizdahr's bodyguard: while fighting against Ser Barristan Selmy, the tip of his arakh grazed one of the wall hangings and hung, leaving him unprotected, then Selmy struck him down.
According to the TV series official pronunciation guide developed for the cast and crew, "Arakh" is pronounced "Ah-rock", as opposed to "Ah-RACK".