A Chaos Warmaster (as opposed to a Lord) must always be used as a fleet commander in any Chaos fleet list that requires the use of a fleet commander. Under no circumstance can a Chaos Lord be placed on the same ship as a Warmaster.

For every 1,500 points in a Chaos fleet, one cruiser from any Imperial Navy fleet list up to 185 points and/or up to six Imperial Navy escorts may be taken. Special weapon rules, Nova Cannon, Chaos Lords, Chaos Space Marines, Chaos ordnance or Daemonship upgrades may not be taken for Imperial Navy vessels used in this manner, and cruisers suffer -1Ld for going renegade. Imperial Navy escorts need not be in a single squadron and may be interspersed within other Chaos escort squadrons if desired. These vessels do not count as reserves; they count as Chaos vessels in all respects.

Leadership

A vessel with a Chaos Space Marine crew will have +1 Leadership (in addition to any other bonuses due to there being a Chaos Warmaster or Chaos Lord on board). Furthermore the maximum Leadership of the vessel is increased to 10.

Boarding and Hit-&-run

The superior fighting skills of the Chaos Space Marines are most apparent in boarding actions. A ship with a Chaos Space Marine crew adds +2 to its roll (this replaces the standard +1 bonus for Chaos vessels) when performing boarding actions, and enemy conducting hit & run attacks against them subtract one from their hit & run result. Hit and run attacks launched by boarding torpedoes, Dreadclaws, Thunderhawks or teleportation originating from such a ship add 1 to their result.

Planetary Assault

Ships with Chaos Space Marine crews in a Planetary Assault mission score two Assault Points for every turn they spend landing troops.

Terminator Teleport Assault

Battleships and grand cruisers with Chaos Space Marine Crews may embark Chosen Terminators for +10 pts, allowing them to roll two dice when conducting hit and run teleport attacks and select which one they wish to count.

Marks of Chaos

A ship with a Chaos Space Marine crew may have a Mark of Chaos, even if a Warmaster or Lord does not captain it.

Capital Ship Squadrons

If capital ships are grouped as squadrons then each squadron may only contain a single Warmaster or Lord and that ship must lead the squadron. Similarly a squadron may not include ships with different Marks of Chaos.

Command

A Daemon ship may never be commanded by a Warmaster or a Chaos Lord. A Daemon ship may never have a Chaos Space Marine crew. Daemon ships cannot carry Exterminatus weapons and do not score any points for landing troops in a planetary assault. Daemonships cannot be used in squadrons. Any Daemon ship may have a single Mark of Chaos with the same effects and cost in points as described in the Battlefleet Gothic rulebook.

Warp Translation

A Daemonship may be kept off table at the start of a game while the rest of the fleet is deployed. In the End phase of any Chaos turn after the first, the Daemon Ship may enter play from the Warp as follows:
Select a friendly or enemy Capital ship, and position the Daemonship within 20 cm of the chosen vessel facing in any direction. Next, roll 4D6 and a Scatter dice and reposition the Daemonship accordingly, keeping the ship on the same heading. A Daemonship cannot be forced to disengage by a scatter roll that places it off the table. If a Daemonship scatters off the table when deploying, place the Daemonship so that its base is completely on the table on the point of the table edge indicated by the scatter dice, facing any direction. If a ‘Hit’ is rolled on the Scatter dice, then the Daemonship arrives on target. The arriving Daemonship is unaffected by celestial phenomena and does not trigger attack by ordnance markers it may happen to land on. If it would appear in contact with an enemy vessel, reposition it by up to 1 cm so that it is out of contact.

Spectral Daemonships

When first placed on the table, a Daemonship is spectral. Any enemy vessel attempting a special order when within 15 cm of the Daemonship is at -1 Leadership (if the ship also has a Mark of Slaanesh the penalties are cumulative). The Daemonship cannot move, shoot, board or conduct any action in any way, though any Marks it may have still take effect immediately. It also may not be shot at, boarded, rammed or have any action done to it while spectral. At the end of any subsequent Chaos End phase the Daemonship may complete the translation to real space on a D6 roll of 2+. This final translation cannot be made if the Daemonship is in contact with an enemy vessel. No actions can be undertaken in the End phase during which final translation occurs. From this point on the Daemonship is solid and fights like a normal ship. If a Daemon ship fully materializes in contact with celestial phenomena, it suffers any effects of those celestial phenomena, such as gas clouds, asteroid fields, etc. before the start of its movement phase. However, if it materializes in an asteroid field, it may then attempt to avoid damage by making a leadership check normally.

Haunting

A Daemonship may disengage at the end of any Chaos Movement phase without having to make any dice roll. It simply drops back into the Warp leaving no trace. A disengaged Daemonship may re-enter play on any Chaos turn following the one in which it disengages. This is done following the translation rules detailed above. When a Daemonship is ‘haunting’ or is spectral it can still suffer damage from fire critical hits. If it was damaged when it disengaged it may be repaired when it returns, roll a D6:

Add +1 to the roll if it is a battleship, and +1 for each full turn the Daemonship spent in the Warp. In addition to repairing damage, they may repair critical hits while in the warp rolling normally, repairing critical damage on a 4+ as opposed to a 6. However, Daemonships may not make repair rolls in the end phase they are first deployed when returning into play. If Daemonships repair enough hits while “haunting” to no longer be crippled, they will still count as disengaged for purposes of victory points but will no longer count as crippled. A returning Daemonship cannot come back with more hits than it could normally have. At the end of the game a Daemonship which disengaged (even just once) will count as having disengaged for Victory points purposes, unless of course it is destroyed or crippled when the normal rules apply.

Daemonships in Campaigns

Daemonships do not automatically regain hits after each battle. They have to be regained either in a game by warp translation or by expending repair points, or they can be withdrawn normally.