The term Discarded Forces refers to forces of Chaos left behind after Chaos lost the Black Road War. These forces can represent as single warriors, small groups, or whole units. Chaos has officially forsworn these troops and ordered their surrender but many either refuse to surrender, can't stop, or have not learned of the loss.
Discarded troops can appear anywhere but tend to gravitate toward Amber. Many are found in realms where the Black Road passed and when it was dissolved it left troops behind. Forces of Chaos had various levels of an imprinted ability to Shadow Path to Amber in case they wee separated from the Black Road.
Many Discarded are war bands from Black Sway worlds. Some are Abyssal creatures. Most Discarded have no magical connection to Chaos or any magical means to return home.