Medusa Siege Gun

Kiss your fortress walls goodbye.

This article is about the Imperial Guard artillery piece. For the cannon carried by this artillery piece, see Medusa siege cannon. For the mythical character (and other things called Medusa), see Medusa.

The Medusa Siege Gun also known as "The Testical Gun, Adrews Bane, The Big Bangy Thing" is a self-propelled artillery piece consisting of a Medusa siege cannon mounted on a Chimera chassis. It's used by the Imperial Guard to breach and collapse fortifications and buildings. Rather than lob shells up and over fortress walls, the Medusa shoots right at them with tremendously powerful penetrating egg shells.

The combination of large shells fired at low trajectories leaves the Medusa in the unfortunate position of having the short range of a direct-fire weapon and the relatively light armor of self-propelled artillery. It needs to be escorted within spitting distance (relative to other artillery pieces) of the fortification to be destroyed, which means that the entire surrounding region must be secured (though this is not impossible for the Guard). The large size of the Medusa's shells restrict it from carrying more than 18 at a time; though one is enough to flatten almost any structure, it still restricts the Medusa to operating where supply lines are firmly established and well-defended.

Because the Leman Russ Demolisher can fire egg shells that are just as powerful (though slightly shorter-ranged) while being better armored and carrying more ammunition, armies in the 41st millennium keep their Medusas as reserve weapons and avoid deploying them as much as possible. Attempts to re-purpose the Medusa have not been successful -- it doesn't have the range to be a true artillery gun, and it's too lightly armored to support infantry at the front lines. Apparently the idea of changing its munitions to be similar to Demolisher rocket-assisted shells or even a Baneblade-cannon round's rockets has not occurred to the Mechanicus. If it did, though, whoever was stupid enough to mention it would probably be executed for heresy. Emperor forbid you suggest they just armor it like a Chimera, accept the reduced speed for supporting impeded infantry, and give it’s gun area a fully sealed armored shell. Commissars do not react well to common sense, efficiency, and competence.

That said, the Medusa or it’s static cannon equivalents are probably great for the Imperial Guard’s legendary stubborn defenses. Keep holding that fucking line!

Variants

Armageddon pattern

The hive world of Armageddon commissioned a special pattern of Medusa with a fully enclosed interior -- not to protect the crew, but to protect the breech and loading mechanisms of the cannon. If there were a cheaper way to accomplish the latter without the former, the Departmento Munitorum probably would have taken it, but fortunately for the Armageddon Steel Legion (and other regiments who use their pattern of Medusa) there wasn't.

Legion pattern

Like the legion-pattern Basilisk Artillery Gun, Space Marines once had the privilege of operating and using artillery that would later be only used exclusively by the Imperial Guard. The Medusa was no exception as its close-range firepower made it popular amongst the siege-happy Iron Warriors. The Legion-pattern variant boasts an exceptionally well-rounded and well-armoured gunshield. Whilst it is still open-topped, the Legion-pattern offers the best protection short of the Armageddon-pattern.

Solar Auxilia pattern

Like the Basilisk Artillery Gun, the Solar Auxilia also had its own unique pattern of the Medusa. Like the Solar Auxillia Basilisk, this Medusa variant uses the chassis of a Leman Russ Battle Tank rather than a Chimera Transport. The result is that the vehicle now has a smaller profile as the gun is situated on the left-side of the driver's seat. The smaller profile does mean that it carries less ammunition, however, as the closed environment now means that space is a premium.

Vanaheim pattern

Vanaheim apparently makes gunshields, and only gunshields. That said, they're much better looking than the default curved plate, so the Adeptus Mechanicus keeps them in business (and we keep buying the model from Forge World). Compared to the Legion-pattern Medusa from the Great Crusade and Horus Heresy, the gunshield is overall less protective and less armoured. But it is still a more sensible design that the open-topped death trap that is, the regular pattern.

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  The fully-enclosed Armageddon-pattern Medusa.

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  The Legion-pattern Medusa.

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  The Solar Auxilia-pattern Medusa.

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  The Vanaheim-pattern Medusa.

Tabletop

The Medusa siege cannon's default weapon is an S10 AP2 large blast with a range of 36" -- the shortest of the artillery pieces, and shorter-ranged than many cannons available to the Leman Russ Battle Tank, but not problematically so for most regular 40K games. The trade-off is that it fires a higher strength and better AP than any Imperial Guard weapon other than the Deathstrike Missile Launcher, and it can be upgraded to fire 48" AP1 Heavy 1 "bastion-breacher" shells for a few points apiece (they roll 2d6 for armor penetration, though they only use the small blast template) -- in short, what it hits, it will destroy.

In 8th Edition, the Medusa was hurt pretty badly by the move away from blast weapons; it kept the higher strength, but it lost the AP advantage (matching the Basilisk at AP -3), its range got cratered even further by losing its mobility, and the Basilisk will just about always do significantly better owing to its higher average hits. Also, only the Armageddon Pattern and the fixed guns have rules any more. Much like the Deathstrike, the Medusa took a pretty steep fall. So, GW brilliantly saw a vehicle that neatly filled its intended niche and nerfed it to mediocrity in the name of Cha- I mean “balance”.

The model was developed by Forge World for Imperial Armour Volume One: Imperial Guard & Imperial Navy, where it was given rules. It became part of the main-line IG army list in the fifth edition codex. Forge World has continued to produce the Armageddon pattern model as well as a static carriage version.