Rules v1.2.3


One of the most taxing parts of a tabletop wargame is keeping track of the states of various aspects of the game. To bound the complexity of this problem in Jovian Wars, there are three major time windows during which a model may be affected by one or more effects or states:

  • During an Activation - Something a player chooses to do may apply some effect or state to a model, and this state will disappear at the end of the current model's activation. These effects should be simple enough to keep in players' working memories and should require no physical memory aids.
  • During a Turn - A model may have an effect that lasts throughout an entire game turn. In this case a Token may be placed next to a model as a memory aid, and most tokens will be removed during a turn's End Phase.
  • During a Game - Any effect or state that lasts the entirety of a game should be tracked exclusively on a model's Unit Card. This provides for a single source of truth when tracking damage, negative status effects, etc. and will keep the play space uncluttered.

Of course, it's never that simple, and some states and state changes do not fit nicely into the above model, such as In Reserve and Embarked. When possible, however, the rules hold to the above three timing windows.

States generally have requirements to enter a state as well as conditions for cancelling a state.


Requirements Entering Cancellation
Exo-Armor Bombing Run Action Destroyed,Interception

An Exo-Armor squadron that has successfully completed Bombing Run may choose to enter the Assaulting state instead of making a free 4" move. The Exo-Armor Squadron is placed in base to base contact with the Capital Ship, i.e. with one edge of its base entirely in contact with the base of the Capital Ship.

If a Squadron cannot maintain base to base contact with a Capital Ship without overlapping, that Squadron may not enter the Assaulting state. You may reposition Assaulting squadrons to "make room" if necessary, but all must maintain base to base contact.

When the Capital Ship under assault next activates, the Assaulting Squadron must either remain in the Assaulting state or voluntarily cancel it and move up to 4" away.

  • Continue Assaulting - Once the Capital Ship has completed its movement, the Squadron owner places the Squadron anywhere in base to base with the Capital Ship, avoiding Overlapping.
  • Disengage - The squadron makes a 4" move to disengage from the Capital Ship at the beginning of the Capital Ship's activation.

If the model chooses to remain in the Assaulting state, it must declare an Bombing action on its next activation.

Assaulting Exo-Armors may only be targeted by weapons with a 0 Macro Rating before Armor is applied or the Engage Point Defense action.

Assaulting Exo-Armors may also be intercepted by a Squadron in their Active turn. This cancels the Assaulting state, the Assaulting Exo-Armor is moved out of base to base contact with the Capital Ship and the Dogfight is resolved normally.


Requirements Entering Cancellation
Boarded by enemy Marines Boarding Action Boarders: 0 or Marines: 0

At the start of of its Activation, a Boarded model must resolve a firefight between the Boarders (enemy Marines) and the defending Marines. Total up the number of Boarded marines--this is the Boarders rating.

Each player chooses one of the following options in secret and reveal their choices simultaneously:

  • Engage - The Boarders or Marines engage the enemy personnel directly, prioritizing their destruction.
  • Defend - Available only to the defending Marines, this represents the Marines securing access to vital ship systems.
  • Sabotage - Available only to the Boarders, this represents the boarded Marines targeting a particular System or System Trait for damage.

If a player chooses Engage, they make an Unopposed Roll with base dice equal to the current Marines or Boarders rating on the Boarded model.

  • [D] results reduce the opponent's Marine or Boarders rating by 1.
  • [T] results reduce the opponent's Marine or Boarders rating by 2.
  • [Q+] results reduce the opponent's Marine or Boarders rating to 0.

Note that a Boarded ship may not Initiate Boarding!

Example: Dave has boarded a Jovian Valiant, which has 2 Marine rating remaining. Dave's total Boarder rating from all the ships which contributing boarding personnel is 3. Dave chooses Engage and rolls 3d6, getting a [D] result, reducing the Valiant's Marine rating to 1.

If the boarding player chooses Sabotage and the defending player chooses Engage, resolve the Engage as above. The Sabotage is resolved simultaneously as an Unopposed Roll with base dice equal to the Boarders rating. Apply the Results as if the attack were made by a Precise weapon.

If the boarding player chooses Engage and the defending player chooses Defend, both players resolve simultaneous Unopposed Rolls as if they had both declared Engage. The defending player, however, Diminishes their results.

If the boarding player chooses Sabotage and the defending player chooses Defend, resolve an Opposed Roll with the boarding player as Primary Player and the defending player as the Secondary Player. Any remaining Results for the Primary Player are applied as if the attack were made by a Precise weapon.

If a model's Marines rating is reduced to 0 and there are Boarders remaining on board, the model is now considered Captured.


Requirements Entering Cancellation
Boarded Marines: 0 Boarding

Control of a Captured model goes to the player who successfully Boarded it, and the Boarders rating becomes the new Marines rating of the ship, to a maximum of the original Marines rating of the ship.

As a Captured model becomes Captured before the original owning player declares moves and attacks or resolves Actions, the new owner may choose whether or not to resolve the chosen action, but may not change the action for this activation.

A Captured model may be subject to a Boarding action by its original owner in attempt to regain control.

  • A Captured ship is worth 1.5x points for its captor at the end of the game for Victory Points Purposes.
  • A Captured ship is reduced to Fire Control: 1.
  • During its activation, a ship may engage in Movement and Attack as normal, taking into account any damage it may have suffered.
  • A Captured ship may only take the following Actions:


Requirements Entering Cancellation
Capital Ship 0 Structure Repair(/action/repair)

A Capital Ship with 0 remaining Structure is considered Crippled.

If a Crippled ship remains on the table, i.e. not Dead or Exploded, it obeys the following rules:

  • A Crippled ship are worth 0 points for Victory Points purposes, unless it successfully Withdraws.
  • A Crippled ship is reduced to Fire Control: 1.
  • During its activation, a ship may engage in Movement and Attack as normal, taking into account any damage it may have suffered.
  • A Crippled ship may only take the following Actions:

While is it not possible under any circumstances for a Capital Ship to cancel the Crippled state by itself, a Capital Ship successfully repaired by a ship with the Dock trait may exit the Crippled state.

Each Crippled ship rolls on the Catastrophic Damage table when:

  • The ship loses its last Structure and enters the Crippled state for the first time.
  • You start the Deployment Phase of a turn.
  • The ship would lose another point of Structure (ships cannot be reduced below zero Structure).

Catastrophic Damage Table

Roll 1d6 + the number of Systems that have been reduced to 0 rating and consult the appropriate line in the table below:

Roll Result Effect
1-5 No Effect See above
6-7 Dead Destroyed, replace with Wreck
8+ Explode Destroyed, resolve Explosion

Models that are Embarked on a Dead model are placed within 1" of the Dead model before it is removed. Models Embarked on a model which Explodes are assumed to be lost in the explosion and count as Destroyed.

Example: An Uller Capital ship is reduced to 0 Structure rating and Crippled. It has zero point defense and thrusters. The attacker rolls 1D6 and gets a [5]. Adding 2 for the system ratings at zero gives a result of 7 and a result of "Dead". The Ullers owner removes it from the table and replaces it with a 2" diameter Wreck marker.


All models within 6" of the exploding ship suffer a Particle Cannon attack as if the exploding ship was armed with Turret arc Particle Cannons for the purposes of calculating arcs and range for Attack Bonus and Armor effects.

The rating of the Particle Cannon attack is as follows:

Range AC AS Macro
<= 3" Structure Structure 2
> 3 Structure Structure 0


Requirements Entering Cancellation
0 Structure,Dead,or Explode --

A Squadron with 0 remaining Structure rating is considered Destroyed and is removed from the game.

A Capital Ship that has suffered the Dead or Explode results on the Catastrophic Damage Table is considered Destroyed and is removed from the game.

Destroyed models are worth 0 points for Victory Points purposes.


Requirements Entering Cancellation
Squadron Hit by Particle Cannon End Phase

A Squadron that has been hit by a Particle Cannon loses one Fire Control rating, to a minimum of 1. Repeated hits by Particle Cannons do not further reduce Fire Control rating. This penalty is removed during a turn's End Phase.


Requirements Entering Cancellation
-- Land Launch

Models start the game In Reserve or Embarked.

Squadrons may be Embarked on any model with the Hangers trait. If the scenario allows, Capital Ships may be similarly Embarked on models with the Dock trait.

In both cases, the number of Embarked models may not exceed the limits as specified by the relevant trait.

If the scenario allows, it is possible to have Squadrons Embarked on Capital Ship that is itself Embarked.

As with the Reserve state, models that are Embarked are considered to be off the table until they are placed on the table with a Launch action.

States which apply to Embarked models are tracked normally, e.g. damage persists, any state that would expire at the end of turn expires at that time, etc.


Requirements Entering Cancellation
Thrusters: 1+ or Fuel: 2+ Evade Action End Phase
  • An Evading model is considered to have the Evasive trait.
  • If the model already has the Evasive trait, the trait now functions at Short Sensor Range
  • The Evading model is considered to have Fire Control: 1.

In Reserve

Requirements Entering Cancellation
-- -- Deploying the Model

Models start the game In Reserve or Embarked.

Model In Reserve are placed off the table until they are deployed in a deployment phase. Models that are off the table may not Attack or use Actions. They are considered to be on approach to the area of operations.


Requirements Entering Cancellation
Defense: 1+, Sensors: 1+, Thrusters: 1+ Silent Running End Phase, Fire Control Expenditure

This model improves it Stealth trait by 1. If it did not have the Stealth Trait, it gains Stealth: 1.

This state is canceled during the End Phase or if the model expends Fire Control.

Station Keeping

Requirement Entering Cancellation
Thrusters: 1+ Station Keep Action End Phase

Station Keeping sets a ship's Speed to 0" and grants a bonus of one [Flex Die] to all attacks targeting this ship.


Requirement Entering Cancellation
-- Withdraw Action, Leaving Play --

A ship that has successfully executed the Withdraw action enters the Withdrawn state and is removed from play.

For the purposes of Victory Points a Withdrawn ship is worth 0.5x its points.