The previous edition permitted Assassins to deploy hidden in scouting Shades. But the wording and the rules changed. To make this clear, we quote the rules from both editions:
7th edition DE book wrote:Special Rules: Eternal Hatred, Khainite, Always Strike First, Poisoned Attacks, Scout
Hidden: An Assassin is a special type of character. He begins the game hidden in one of the following units: Dark Elf Spearmen, ...., Shades, .... Make a note of which unit the Assassin is hiding in.
A hidden Assassin is not placed on the table during deployment, but is revealed later in the game. If his concealing unit is wiped out or flees from the battlefield before he is revealed, the Assassin is also lost and counts as a casualty. There is no other way the Assassin can be harmed before he is revealed.
Hidden Assassins may be revealed at the beginning of any of your turns or at the start of any Close Combat phase. Declare that the unit contains an Assassin and place the model in the front rank. ....
Whereas now, it reads:
8th edition DE book wrote:Special rules: Always strikes first, Hatred(High Elves), Immune to Psychology, Murderous Prowess, Poisoned attacks
...
Hidden: An Assassin can choose to deploy 'hidden' within another friendly Dark Elf infantry unit (but not Harpies) - make a note of which unit is concealing the Assassin.
<second paragraph is the same as the second paragraph from 7th, to the letter>
Hidden Assassins may be revealed at the start of any of your Movement phases, or at the start of either player's Close Combat phase; declare that the unit in question contains an Assassin and place the model anywhere in the front-rank of that unit ....
Conclusions from RAW
- Assassin is a character, and deployed as such
- Assassin can deploy with the rule "hidden", but it is still a deployment.
- Assassins no longer have the "scout" special rule.
Feedback from other communities
From Warhammer.co.uk
hewhorox wrote:The rules said something like the assassin is deployed with an infantry unit (but not harpies.) this seems to indicate that the model is deployed just not placed on the table and therefore it should follow the normal rules for deployment that it does not have specific exemptions from.
This argument implies that the deployment for the Assassin occurs before the Shades. He is "deployed" following all restrictions of a character but can use the "hidden" rule. The Assassin is free to hide in any unit on the table. The hidden rule (and lack of a scout rule) does not grant the Assassin the means to deploy in a unit not already on the table.
From Warhammer.fr
This argument is written in the language of France which I shall not utter here, but it means:
An Assassin can choose to deploy hidden
This implies the Assassin is deployed, following all rules for deployment with only the exceptions listed in the hidden description.
Proposed conclusion
1) An Assassin does not have the scouting rule, granting him an exception to deploy out of sequence. He is deployed together with all other characters, and while "hidden" permits him to hide, he must be deployed in a unit already on the table.
2) As the Assassin lacks the scouting rule, he is restricted by all regular deployment rules fitting for a character in the selected scenario. The rule 'hidden' does not specify an exception to this.
Can an Assassin hide in scouting Shades? No.