Disguise

At the start of the game Clan Eshin Assassins can conceal themselves in Skaven regiments, disguised as ordinary warriors. Once the regiment enters combat the Assassins cast off their disguise and leap into the fray. You can conceal up to two Assassins in a regiment, but remember to make a note of which regiment they are hiding in.

The Assassin models are not placed on the table with the rest of the troops, but are assumed to move along with the unit until revealed. In this way the enemy doesn't know where your Assassins are lurking until they strike.

Attack

The Assassins are revealed once their regiment is fighting in hand-to-hand combat. The player declares that his regiment conceals Assassins and places the models in a rank where they can fight, removing other models from the front rank to make room for them if necessary.
Because they attack by surprise on the first round of combat, the Assassins fight before any other models, regardless of initiative and who charged into combat. The Assassins can fight any model their base is touching, so it is usual to place them next to an enemy leader or other important character.

Weeping Blades

The weapons carried by a Clan Eshin Assassin incorporate warpstone and baneful spells in their construction so that they constantly weep a deadly corrosive venom. The venom burns through armour and hits from an Assassin have an extra - saving throw modifier, so with their strength of 4 they have a saving throw modifier of -2. The caustic potency of the venom means that each hit causes not one wound but D3 wounds.

Further Fighting

After the Assassins have attacked they can be attacked by enemy models in the normal way. Once an Assassin has been revealed it remains with the regiment and will continue to move with them and fight as described. In any round of combat an Assassin can always choose where to fight within the regiment and can be repositioned to take on enemy characters if the player wishes.

Leadership

The Assassins remain with their regiment and the regiment continues to take leadership tests using its own leadership value. Assassins are not leaders but skilled murderers, so their leadership value is never used by the regiment they are with.

If the regiment is broken, forced to flee, or subject to some other unfortunate psychology or leadership based test which it fails, the Assassins can either remain with the regiment and suffer the consequences or pass a separate leadership test and transfer to another regiment within 6".