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Space Marine Review: Thunderfire Cannon

7 Minute Read
Feb 22 2018

Dive in today with a review of the Space Marine army’s premier artillery piece, the Thunderfire Cannon.

Thunderfire Overview:

Hi everyone, Michael here. The Thunderfire Cannon is a fairly recent addition to the Space Marine arsenal. It is one of the few weapons in the Space Marine army that does not need line of sight, making it a valuable addition to the army. It has a solid damage output for its cost, but also has access to one of the best stratagems available in the codex, capable of seriously crippling selected enemy units when used right. The Thunderfire Cannon consists of a Cannon and Techmarine Gunner, costing 121 pts in total for the unit.

I would give the Thunderfire Cannon the Competitive rating. It has a good damage output, able to strike almost anywhere on the board, and correct use of its stratagem could be game winning in the right circumstances.


  • Thunderfire Cannon- 60″, Heavy 4D3, S5, AP -1, 1 damage. Can target models not visible to the firing model.
  • Techmarine Gunner has Bolt Pistol, Plasma Cutter (essentially an assault Plasma Pistol), a Flamer and two Servo-arms.
  • Servo-arm- Melee, S x2, AP -2, 3 damage, -1 to hit. Each servo-arm can be used to make one attack when the bearer attacks.


  • And They Shall Know No Fear
  • Artillery- Can only fire its ranged weapon if there is a <Chapter? Techmarine Gunner within 3″. A Techmarine Gunner can only fire a single cannon per turn. If there is no Gunner within 6″ of the Thunderfire Cannon at any point, the Cannon is removed from play.
  • Techmarine Gunner- When set up, the Gunner must be placed in coherency with the Thunderfire Cannon. After that, he is treated as a separate unit.
  • Blessing of the Omnissiah- At the end of the movement phase, a Techmarine Gunner can repair a single <Chapter> vehicle within 1″. The vehicle regains D3 lost wounds. A model can only be repaired once per turn.


The Thunderfire Cannon puts out some decent firepower each shooting phase. Each turn, it will fire between 4 and 12 shots (with an average of 8 shots per turn) at S5 and AP -1. Hitting on a 3+, you will be killing around 2 Marines a turn on average, or 3 Guardsmen. That doesn’t sound too great for 121 pts, but the real strength of the Thunderfire Cannon is in disrupting your opponent’s battleplan through the use of the Tremor Shells Stratagem (which will be discussed below).

The Thunderfire Cannon is quite resilient to enemy firepower as well. With T6, four wounds and a 3+ save, it will take some decent firepower to destroy it. In addition, the Blessings of the Omnissiah from the Techmarine Gunner can be used to heal a damaged Thunderfire Cannon, helping to increase its longevity on the battlefield. However, the best defence against enemy firepower is the huge range of the Thunderfire Cannon (60″) and the fact it does not need line of sight to the target. This means you can stick the Cannon behind some line of sight blocking terrain deep in your deployment zone and still be able to reach most of the table with its shooting attack. This makes the Cannon great for sticking on a backfield objective and staying in place for the whole game.

The Thunderfire Cannon works well deployed in the corner of board in your deployment zone. From there, it can still reach most of the enemy units it would want to fire at thanks to its increased range. Just remember not to leave any gap behind the cannon that enemy deep strikers could potentially land in to fire at the Cannon or assault it. It also helps to have at least one unit (or more realistically the rest of your army) in front of the Cannon to stop it from being assaulted and stopping it from firing.


Once deployed, the Cannon should be pretty static for the rest of the game. It can move and fire, but with a 3″ move, it is not going to be going anywhere fast. It is also a good idea to keep the Techmarine Gunner behind the cannon. He cannot be targeted easily thanks to the Character keyword, meaning your opponent will have to target the tougher cannon to take it out of action. As mentioned above, the Gunner can be used to heal the Cannon each turn if it is not destroyed outright.

Deploying the Cannon and Gunner next to another of your vehicles is also useful, allowing the Gunner to choose which vehicle to heal and keep them alive for longer. This works well for other long ranged firepower vehicles, such as the Whirlwind or a Lascannon Predator.

Meet the Tremor Shell

For me, the real strength of the Thunderfire Cannon and the reason you take one in your army is the Tremor Shells stratagem. This stratagem costs 1 command point and is used when you select a Thunderfire Cannon to shoot in the shooting phase. You must subtract 1 from any wound rolls, but if the Thunderfire Cannon hits the enemy unit, then in its next turn, the target unit must halve its Movement characteristic, as well as any Advance or Charge rolls. This has no effect on units with the Fly or Titanic keywords.

For me, this is a bargain for only 1 command point, and in the right situation can seriously affect the ability of an opponent’s unit to move on the battlefield, either for grabbing objectives or charging your units. Halving all the movement of a key enemy unit can be key to winning a game in 8th edition, and there are so many choice targets in a number of armies to target with the Tremor Shells. It’s just a shame you can only use it once per turn! With a key unit effectively stalled for a turn, you don’t have to devote any more firepower to that unit if you don’t want to, allowing the rest of your army to target other threats to your units. The stalled unit can then be targeted once these other threats have been weakened or destroyed.

The Stratagem can be great for fast or tough assault units, such as Genestealers, Hormagaunts, Khorne Bezerkers, Daemonettes, Harlequins, etc. What is also great is that it continues to work for enemy psychic powers or abilities, such as Da Jump, Warp Time or Hive Commander, seriously decreasing their ability to move around the board to grab objectives or assault your units. With the correct use of the Stratagem each turn and your own units’ movement, it can be possible to effectively keep a key enemy unit out of the game for several turns if you are lucky, and the ability cannot be easily countered, like a psychic power.


Another great use for the stratagem is if your opponent employs a large screening unit in their deployment zone, such as Grots or Conscripts. By using the Stratagem on such a unit, you can block the movement of other units in the army, penning the enemy army into their own deployment zone in many cases. While this may not bother a static shooting army too much, it will stop your opponent from moving to grab objectives or assert board control for bringing in their own deep strikers in future turns.

Unfortunately, the Tremor Shells Stratagem is not going to work for every unit in your opponent’s army. It does not work on units with the Fly keyword (which makes sense). This is annoying, as a lot of times it is these units that you will want to slow down and stop them from getting to your lines. It also cannot be used on units that arrive by some form of deep strike rule on the first turn they deploy. However, in subsequent turns, it is a nice way to keep these units from moving to a better position to threaten more of your army.

Worth It?

I think that one Thunderfire Cannon is about right for the army. One Cannon gives you range for most of the board, and is not such a big threat that your opponent will go out of the way to destroy it. Two Thunderfire Cannons on opposite sides of your deployment zone will give you full board coverage, but you can only use the Stratagem once per turn in competitive play. In this situation, the second Cannon is a bit wasted, as the damage output from the Thunderfire Cannon is decent, but not amazing.

The Techmarine Gunner has some decent firepower and combat ability. A Plasma Cutter and Flamer can provide some good firepower against a range of enemy units, with the Flamer providing some useful overwatch firepower. The two Servo-arm attacks are also useful, hitting on a 4+ at S8, -2AP and 3 damage. This can give the Techmarine Gunner some strong close combat punch if you need to. However, I would expect him to be doing much during the game other than making sure the Thunderfire Cannon is firing and occasionally repairing it. If you find him in range to shoot or get into assault, things have probably gone quite wrong.

Overall, I think the Thunderfire Cannon is a solid addition to a Space Marine army. It is not too expensive and doesn’t have the greatest damage output each turn, but it is the Tremor Shells stratagem that makes it a really good competitive choice to add to your army.

~Do you use Thunderfire Cannons?


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Author: Pablo Martinez
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