The second Khesh’dar tradition is that of the Shaarat’khesh (“Silent Blades”), spies and assassins trained to operate within cities. Both usually operate covertly, disguised to blend in with the local goblin population. However, each order has a distinctive half-mask that is worn over the lower face during formal interactions.
Source: Exploring Eberron
"Even the smallest blade can slit a throat."
The shaarat'khesh ("silent blades") are an elite order of spies and assassins. The shaarat'khesh have long practiced a martial art designed to transform an unarmed goblin into a living weapon. This order can trace its roots back to the ancient Dhakaani empire. At the height of the empire, the shaarat'khesh served as the hand of the emperor, bringing silent death to traitors and criminals. Once the empire fell, the shaarat'khesh became mercenaries, selling their services to any warlord with gold. As the Dhakaani age came to an end, the Silent Master called upon the shaarat'khesh to withdraw into the depths of their mountain fortress, leaving the remaining warlords to squabble over the ruins.
By ancient tradition, the Silent Clans do not take sides in any conflict. Instead, they act as mercenaries, providing their services to all sides and fighting their brothers when they face one another on the battlefield. This reputation for complete impartiality and reliability has kept the khesh alive for thousands of years. Its own clan will execute a goblin that betrays the secrets of a client. Generally speaking, one must be born into a khesh clan to learn its ways, but on rare occasions skilled goblins from other clans have gained admission to one of the Silent Clans.
Now, thousands of years later, the Heirs of Dhakaan have reemerged -- and the shaarat'khesh have returned with them. For the past century the goblins have been studying the nations of modern Khorvaire, moving among city goblins and establishing safehouses across the land. All of the clan lords rely on the shaarat'khesh for information, and many have sought to win the allegiance of the assassins. But the Silent Master has maintained a position of neutrality. The shaarat'khesh are the servants of the empire. But until the clans unanimously agree on an emperor, the silent knives treat all clans equally and demand payment in gold. The shaarat'khesh do not accept every contract; as a rule they do not assassinate Dhakaani clan leaders or dirge singers. But once the silent knives take an assignment, they see it through to the end, even if this means fighting other members of the shaarat'khesh. It is this impartiality and dedication that has allowed the clan to survive amid the warring heirs.
The Dhakaani are an agnostic people, and the shaarat'khesh have little interest in gods or arcane mysteries. A goblin initiate seeks to become the perfect living weapon: swift, silent, equally deadly with fist and blade, whose focused mind can overcome any weakness of the body. While he may feign emotions when it serves his cause, a silent knife is cold and calm, and he always remains focused on his next task.
As a general rule, a goblin must be born into the clan of the shaarat'khesh to learn the ways of the order. However, exceptional goblins have been adopted by the clan, and they even have a few members of other races -- most notably changelings.
All Dhakaani goblinoids know of the shaarat'khesh. Other characters must make a successful bardic knowledge or DC 25 Knowledge (history) to see whether they have heard of the order.
Organization: A student of the silent arts carries the title of shaarul (dull blade). Upon completion of his training, the monk takes the title of tar'khesh (silent hand) or il'khesh (silent eye), depending on whether his primary focus is combat or espionage. Monks with assassin levels are known as mula'duur (bringers of sorrow). Clan decisions are made by a council of elders; the leader of this council holds the title of guula'khesh (silent master).
Shaaruls are generally 1st-level monks. To attain the title of tar'khesh or il'khesh, a character must be a 2nd-level monk or 1st-level monk/1st-level rogue with 5 ranks of Hide and Move Silently.
Monasteries: The il'khesh have spread across Khorvaire over the past century, and the silent knives have eyes hidden in many of the great cities of the Five Nations. Any city with a significant goblin population may contain a shaarat'khesh safehouse. However, only one true monastery exists: the fortress hidden deep in the Seawall Mountains, home to both the monks of the shaarat'khesh and the noncombatant members of the clan.
Character Development: The majority of the shaarat'khesh divide their character levels between rogue and monk, using the Monastic Training feat. Others follow the pure monastic path until 6th level, when they can become assassins (provided they meet the prerequisites). The shaarat'khesh rely on speed and stealth, using surprise to strike an opponent with devastating sneak attacks. Traditional feats include the following: Combat Expertise, Dodge, Improved Feint, Monastic Training (Rogue), Skill Focus (Bluff), and Stunning Fist. Monastic skill training focuses on Hide, Move Silently, and Tumble; Bluff, Disguise, and Gather Information are also considered to be important talents.
Knowledge (local) and Knowledge (history) are class skills for shaarat'khesh monks. These take the place of Knowledge (arcana) and Knowledge (religion).
Source: http://archive.wizards.com/default.asp?x=dnd/ebds/20041213a