Scenario. The Arrival of Ahriman
By Chris Lucking. Ahriman by Chris Lucking and James Parry

- = from Battle Fleet Gothic Mag. #6 = -

This scenario describes the one of the most significant battles of the Cerberus Shroud. Though it was dismissed by some commentators as being unimportant at the time, subsequent events revealed that a different outcome here could have made a tremendous difference to the war. It introduced one of the most notorious warleaders of the 41 st Millennium to the Cerberus War: Ahriman, Chief Librarian of The Thousand Sons Chaos Marines and Arch-Sorcerer of Tzeentch.


‘We are undone. He is here.’ - The last astropathic broadcast received from the patrol cruiser Nevsky prior to its destruction.

Following an earlier, secret foray into the Cerberus Shroud in a single vessel, Ahriman, the mightiest mortal Sorcerer of Tzeentch, returned openly and in force. Where before he had been content to gather information by a variety of subtle means, he now turned to the power of his ships and warlords and his own magics to serve his goals. Riding a warp current into the fringes of the Amaranth Sub-Sector, he emerged in the Willow system and immediately engaged the Imperial forces there.

This was the first time he made known his presence in the Sector and he did it by annihilating the Imperial fleet that stood in his way. The Naval vessels never really stood a chance against him but were adamant that the Arch-Sorcerer’s progress into the Sector would be delayed long enough for warnings to reach their comrades in other systems. At the time the Willow system had recently been placed back under the control of the Imperium. The Navy’s hold on the system was not strong, however, and following this battle the primary habitable planet, Willow B, fell to Chaos. The Navy’s only victory in the whole affair was the destruction of Ahriman’s flagship Severed Dreams through sustained – and lucky - nova cannon bombardment by the Dominator-class cruiser First Strike.

Ahriman survived this, through arcane means, however. He spent little time consolidating his hold on the system. Almost immediately his forces re-entered the Warp and jumped to the adjacent system of Raga and then onwards, deeper within the Sector, following an inconclusive clash with Necrontyr forces there. Ahriman’s goals were still unclear at this stage of the Cerberus War but it is interesting to note that unlike all of the other recent arrivals to the sector, he seemed to know exactly where he was going…


The game is based on The Escalating Engagement scenario presented in the BFG rulebook, with some differences to represent actual events.


Imperial forces should be chosen normally, with the following restrictions. Up to 2000 points with a maximum of 1 battlecruiser, 1 Nova Cannon-equipped vessel and 1 carrier with up to 4 launch bays can be taken. Escorts and other cruisers may be taken as normal. No battleships were present at the historical engagement. The Imperial forces should be grouped into 5 divisions as per normal.

Chaos forces may take up to 2000 points with a maximum of 1 battleship. No Planet Killer or Blackstone fortress may be taken. The Chaos player must take Ahriman (see below for his rules) as the commander of the Chaos fleet. Only Marks of Tzeentch may be taken by the Chaos Warmasters and Lords present. 1 division of up to 300 points of ships should be created.

Historical Imperial forces

1 Admiral, Ld 9, with 2 extra re-rolls
1 Overlord class battlecruiser ‘Triumph’
1 Dictator class cruiser ‘Vanguard’
1 Dominator class cruiser ‘First Strike’
1 Tyrant class cruiser ‘Implacable’.1 Gothic class cruiser ‘Furious’
1 Lunar class cruiser ‘Challenger’
3 Dauntless class Light cruisers ‘Nevsky’, ’Hunter’, ’Rapier’
3 Firestorm class frigates
3 Sword class frigates
3 Cobra class destroyers

Historical Chaos forces

Ahriman (see below)
1 Chaos Lord, Ld 8, Mark of Tzeentch
1 Despoiler class battleship ‘Severed Dreams’
1 Repulsive class grand cruiser ‘Treacherous’
1 Hades class heavy cruiser ‘Vengeance’
1 Devastation class cruiser ‘Scourge’
1 Carnage class cruiser ‘Eliminator’
1 Murder class cruiser ‘Malicious’
1 Slaughter class cruiser ‘Eradicator’
3 Iconoclast class raiders ‘Black Asps’
2 Idolator class raiders ‘Avengers’

Special Rules

The Chaos fleet is commanded by Ahriman. He has the following rules:

Ahriman, Chief Librarian of The Thousand Sons

Ahriman is the commander of the Chaos fleet and must be placed upon its most powerful vessel. He will use his vast magical powers and strength of will to guide and support his ships but woe betide any of his followers who dare fail him.


Ahriman has a Leadership value of 10 and gives his fleet one re-roll per turn, in exactly the same way as Abaddon (see rules in Warpstorm and White Dwarf).


Ahriman's fleet is allowed to re-roll a single Command check or Leadership test each turn. Ahriman's awesome reputation and dogged determination ensure that there are seldom any failures in the chain of command. When there are, the consequences are likely to be dire.


To represent the price of failing the Arch-Sorcerer of Tzeentch, he also uses Abaddon's 'You have failed me for the last time' rule:

"You have failed me for the last time..." Ahriman does not tolerate failure, as many of his followers have discovered to their cost. If Ahriman's re-roll is used for a Command check or Leadership test on another ship or squadron and the test is failed a second time, he will become angry - very, very angry! In the Chaos Shooting phase Ahriman will direct at least half the available firepower and lance strength of the ship he is commanding against the weaklings who have failed him (assuming the worthless scum are within range and fire arc). Resolve the attack as normal, just as if Ahriman's vessel were an enemy.

The victims of his wrath (assuming they survive) will be suitably chastised and gain a +1 Leadership increase for the remainder of the game. The Leadership bonus will only take effect once (after that the crews are working as hard as they can!). If the object of Ahriman's wrath is not in range and/or fire arc he will leave them to their fate - Ahriman's re-rolls may no longer be used on it. This means that no further Commander re-rolls may be used on the ship or squadron unless it is carrying its own Chaos Lord with a Mark of Tzeentch.

Should this dreadful failure occur on Ahriman's own ship, it will lose one damage point as the Thousand Sons Legion massacre those who failed him. No Leadership increase is gained.

‘I’ll be back’: As Ahriman is quite important in this campaign, even if his ship gets blown to bits and then implodes into the Warp, he may still return when you least expect it…

Sorceror: Ahriman’s magical power is so great that he can affect even as large a target as an Imperial star ship! He has the following magical abilities in a Battlefleet Gothic game:

Blessing of Tzeentch: All enemy vessels firing at his ship suffer a right column shift on the gunnery table;

Ward of Chaos: All enemy ships within 15cm of his own count as having one Blast Marker on their base;

Daemonic Horde: once per game you may unleash a horde of Tzeentchian daemons against your foes. Roll a D6 and then roll that many dice to hit vs. any one enemy ship's armour value. Shields do count against any damage caused and check for Critical Hits as normal.

Please note that as Ahriman is an unofficial addition to the BFG Game, he may only be used with your opponent’s permission in games other than this one. He must always be the chief Warmaster of your fleet and placed aboard its most expensive vessel. What happens when you take Ahriman and Abaddon (who also must always be the chief Warmaster & be placed on the best ship) in the same fleet is outside the scope of this scenario but it would probably be really nasty…

Other special rules for this scenario are dealt with in the appropriate section.

Battlezone, Set-up and First Turn

Celestial phenomena are determined as normal, and the starting forces deployed normally. Historically, the Slaughter and the Iconoclasts were used to bait the trap and the Dauntless-class Nevsky found them first.

Ahriman’s precognitive skills allowed him to group his forces very effectively, leaving the scattered Imperials to be destroyed piecemeal..To represent this the Imperial forces select and deploy their reinforcements as in a normal Escalating Engagement.

The Chaos player places 1 contact marker on the table edge of their choice at the end of their first turn. This marker represents the entire of the rest of the fleet, which arrives at the beginning of turn 2. The Imperial forces are in a desperate situation, they should be considered to have the ‘Blood Bond’ subplot from the Legacies of War table.

The Chaos forces are trying to break through and get Ahriman to the Shroud as fast as possible, treat the ship that Ahriman is on as being on a ‘Desperate Mission’.

Victory Conditions

To give the Imperial forces a reason to play this mission rather than just sitting around getting massacred the victory conditions are altered as follows:

Imperial forces get 75% of the victory points for crippling the Chaos vessels, rather than the normal 25%. Chaos forces get no points for holding the field.

Other gaming ideas

Ahriman is such a major character in the 41st Millennium that he lends significance to any scenario in which he takes part, whether large or small. He can also be used indirectly, as a major player in the background of a scenario. He will fight against any race that might have further information on the secrets of the Cerberus Shroud or that dare to stand in his way. He will even fight other Chaos fleets – either to force them into his service or to prevent them from hindering him.

His fight against the Necrons in Raga was a large affair – a 2,500 pt. Fleet Action. After a few turns, both sides chose to Disengage but who know what the result would be if you fought the battle yourself? Following the battle at Raga, he jumped, seemingly at random, into other Sub-sectors, searching for clues on how to access the forbidding Shroud Nebula at the Sector’s heart.

Ahriman is of course a Warhammer 40,000 Special Character and could figure in many 40K battles in the Cerberus Shroud, whether he is leading a small Thousand Sons expeditionary force or a huge Chaos land army. Ahriman, like many of the wiser or more driven fleet commanders of the Cerberus War, is actively seeking out artefacts from, and information about, the Sector’s mysterious past and could clash with any other army in pursuit of these. I see an ork/Chaos 40K game on the horizon…