The Logrusfoils are the Chaosian counterparts to the Patternblades; Primal Weapons of Chaos, each containing a piece of the Logrus. They constantly shift in form but possess a unity of function, and like the Patternblades each has a signature power, although unlike them they seem to have no elemental affinity. They are capable of igniting the blood of those descended of the Blood of Order. They are the sibling blades of the Logrusfoils of New Chaos, and are numbered among the [Great Weapons]?.

Two of the Logrusfoils, Thought and Memory, were used by Annadil to open the Gate of Revolution beneath the Air Pattern of Tir'Na-Nog on the Second Day of Darkness. These two Logrusfoils appear, along with the Patternblades Greyswandir and Werewindle, appear to be the 'keys' neccessary to open the Gate.

There were 13 Logrusfoils forged in total for Dios's children, but the blades have dropped repeatedly on and off the stage of history over the centuries.

At the time of Forth the Nine Riders, in the aftermath of Logruswreck, the disposition of the known Logrusfoils are as follows: