A space combat mini-game and RPG supplement.

Why should you care?

You want this game if…

How’s it Play?

This game has two major aspects:

Every ship you can build will have different strengths and weaknesses. You’ll want to anticipate the build of your opponents and try to build the best counter to them.

Once in the fight, one of the most important decisions you’ll make is where you apply the damage dealt to your own vessel. Choosing which of your ship’s systems take damage can be the difference between victory and defeat.

Dice introduce an element of luck to the game to help keep things interesting. In space, precision is life but chaos is king!

Required Materials

To play Cosmoforce, you’ll need:

Build a Ship

First, you’ll want to secretly build a space ship. Don’t show the other players what you’re doing.

Start off selecting one of the three ship classes. Each class of space ship has a number associated called its “Size Modifier.”

Fighter 1A small, nimble vessele
Cruiser 2Medium weight gun-ship
Capital Ship 3Massive, durable ship

After you select your ship’s class, you will need to load out your vessel with “Systems.” Systems are components of the ship that make it work. Your ship’s roster has ten system slots which you can fill or leave empty. Fill a slot by writing the name of the system in that slot. Possible systems include…

Armor Protective plates to absorb damage
DissipatorRadiators to help manage heat
Engine Propulsion system to move and steer your ship
Habitat Equipment that helps keep crew alive
Laser Weapon that cooks enemy ships
Missile Weapon that blasts enemy ships

In addition to these, each class of ship has a special system that only it can mount. These systems are…

AfterburnerFighterEfficient propulsion systems for lighter ships
Hangar CapitalWeapon system using remote controlled drone ships
Railgun CruiserWeapon that punches holes in enemy ships

After you’re finished mounting systems on your ship, you’ll need to do a little bit of math…


Your ship’s mass determines how light and maneuverable it is. The lighter the ship, the easier it is for you to dodge enemy fire during combat. A ship’s mass is calculated by the following formula:

Mass = Size Mod x Number of mounted systems

This means that the more equipment you load your ship with, the heavier and more sluggish it will be. Here is a chart showing the rates of mass for each class…

1 12 3
2 24 6
3 36 9
4 48 12
5 510 15
6 612 18
7 714 21
8 816 24
9 918 27
10 1020 30

Crew Complement

Your ship will have one or more crew members aboard that help operate the vessel. The number of crew your ship will have is determined by the following formula:

Complement = 1 + ( Size Mod x Habitats )

Thus, larger vessels will be able to support larger crews.

0 1 1 1
1 2 3 4
2 3 5 7
3 4 7 10
4 5 9 13
5 6 11 16
6 7 13 19
7 8 15 22
8 9 17 25
9 10 19 28
10 11 21 31

Note: Having 10 habitats is not recommended.

Crew State

For each crew that your ship has, place one Crew Token on the roster in the “heads” position to denote that the crew is ready to work. Crew tokens begin in the standby box on your roster.

If the crew is ever harmed, flip the token over to the “tails” position to denote that they are hurt.

If crew that are already in the hurt state are harmed, that crew is killed which is represented by removing the token from the roster entirely.

Initial Speed & Thrust

Your ship will need at least one propulsion system mounted on it. There are two kinds of propulsion systems in the game:

Each propulsion system contributes Thrust which is good for not only raw acceleration, but also for maneuvering and finer control of your ship.

The Thrust contributed by each system is as follows…

Engine +1
Afterburner +2

Your ship will begin the game with a Speed based on the cumualitve thrust contributed by all working propulsion systems. If your ship’s thrust later changes (as when engines get damaged), the speed will remain the same unless something changes it (per Newton’s First Law).

Speed = ( 3 - Size Mod ) + Thrust

Initial Heat

Contrary to what pop-sci-fi TV tells you, one of the biggest challenges any space craft faces is managing heat. Your ship will start with a number of Heat Tokens on the roster equal to the number of Engines plus the number of Afterburners mounted.

Unlike crew tokens, heat tokens do not have different states so the “heads/tails” position is unimportant.

Rolling Dice

In space, precision is life but chaos is king! Correct calculations are the difference between victory and defeat. Dice values represent variance in your calculations so you want them to be low.

This game uses eight-sided dice exclusively. You may use one or more dice in any given roll (depending on the context).

After rolling dice, discard all of them with values of 7 or 8. These are energy lost to heat, human error in operations, and other inefficiencies that plague all space ship operations.

After discarding dice, any dice that remain are called effective dice and the more of them you have, the better.


Sometimes, you can get lucky and things can turn out better than you’d expect. One of the ways this can manifest is with cascading dice. Every time a die rolls a 1, you may immediately roll another die and add it to the roll – treating it as if it were part of the original roll; discarding it if it’s a 7+.

Extra dice that roll 1 can themselves cascade, making it possible to turn up with far more dice than you’d initially rolled.

Rolling to Shoot

In combat, your ship will be traveling so fast and shooting across distances so vast that Special Relativity is working against you. Shooting is not a certain success and thus, calls for a dice roll.

Rolling to shoot follows all the steps described above but it has an extra step. If the ship you’re shooting at is capable of maneuvering, it will be actively trying to avoid your shots.

If the target ship’s speed and thrust are both 1.0 or higher, your target will be avoiding your shot. In this situation, the cumulative values on all your dice can not exceed the target’s mass. Discard dice from your roll until the values on the remaining dice add up to less than or equal to the target’s mass.

If a ship has a speed of 0, this rule does not apply and your target’s mass does not limit your attacking dice values. If a ship has a Thrust of 0, it also does not apply.

Once you’ve eliminated all appropriate dice, remaining effective dice are called hitting dice and each one forces the target to apply 1 damage.


When all players are done building ships, simultaneously reveal your rosters and begin the first Round.

A round consists of one turn for every player in the game. The player whose ship has the highest speed will take the first turn. The player with the second-highest speed will take the second turn, and so forth, leaving the slowest ship to take the last turn before starting a new round.


When two ships have the same speed, the one with the lower mass is considered to be faster. If two ships of the same mass have the same speed, you must immediately resolve the tie by maneuvering.

To maneuver, all ships who are tied for both speed and mass must roll dice. The number of dice rolled is equal to the total amount of Thrust on the ship’s systems +1. Each effective die adds +0.01 to the ship’s speed.

Repeat these rolls until all ties are broken.

Maneuvering is always done immediately as a tie appears. This means if that two ships become tied for speed (and have the same mass), as a result of a Burn Engines action, maneuvering interrupts the flow of play in that moment and force maneuvering rolls.

Executing Turns

Each turn involves the following steps executed in the following order:

Resolve Ongoing Repairs

If you have any crew assigned to repair systems on your ship, each ready crew so assigned clears one damage mark from the system to-which they are assigned.

You may choose to remove that crew token from the system and place the token in the Standby box, or leave it there to continue repairs.

Manage Heat

For each working Dissipator mounted on your ship, remove one Heat Token from your roster.

If any heat tokens remain, roll one die for each. Every effective die forces you to harm a crew.

Check for Collisions

There are two reasons why your ship may be at risk of collisions:

In either case, for each whole point of speed you have, you must roll one die. Each effective die forces you to apply 1 damage to your ship.

Take Actions

You are allowed to take two actions on your turn. They can be any of the following (including two of the same action):


Select another ship as your target and a type of weapon system mounted on your ship. You may use any number of working systems of that type to perform the attack. Roll to shoot with the number of dice specified by that weapon system. Each hitting die forces the target to apply 1 damage.

Weapon systems that can be used in an attack include:

Attacking with Hangars

A hangar houses dozens of tiny, remote controlled drones. These unmanned vehicles are capable of maneuvers that would be unsafe for manned vessels.

When attacking with hangars, roll to shoot with one die for every hangar system used.

Against smaller vessels, the maneuverability advantage of the drones really shines. If the target of this attack has a mass inside 15, each hitting die inflicts 3 damage instead of the usual one.

Attacking with Laser

Emitting focused beams of radiation with pinpoint accuracy makes this system a popular weapon – even in spite of its tendency to generate dangerous heat.

When attacking with lasers, roll to shoot with one die for every laser system system used. If any of your attacking dice roll values 7+, that laser overheats and you take a heat token for each such die.

In addition to the usual damage, each hitting die forces the target to take 1 heat token.

Attacking with Missile

Missiles hone in on their target and detonate a high yield explosive. They’re so effective, people are willing to take on the risks of carrying such dangerous ordinance on their ships.

Roll to shoot with three dice for every missile system used.

If you roll two or more dice with values of 8 during an attack, your missile system becomes Depleted and you denote that by marking them as destroyed (filling in both damage boxes).

Attacking with Railgun

Railguns are long tubes made of electromagnets that propel a massive slug at high speeds. These enormous cannons can span the entire length of their ships and require precise maneuvering to use in battle.

Roll to shoot with one die for each railgun system used, or with three dice for each system if the target is slower than you.

Burn Engines

Add as many heat tokens to your roster as your ship’s Size Mod. You may then increase or decrease your ship’s current speed by any amount up to your ship’s total Thrust +1.

Conserve Energy

By taking some time to do absolutely nothing, you give your radiators a chance to vent off a little more heat. Taking this action allows you to remove 1 Heat Token from your roster for each working dissipator mounted.

Heal Crew

Taking time to use the medical facilities of your ship can help bring hurt crew back into action: For each Habitat used with this action, flip one hurt crew token to the ready position.


When things get desperate and you’re willing to sacrifice your ship to destroy the enemy, ramming is always an option.

Select a ship to be your target. The target may immediately choose to evade your ramming attempt by taking any amount of heat tokens. Roll one die plus another for each whole point of speed your ship has but for each heat token the target took to evade, roll one less die.

For each effective die in this roll, both you and the target must apply one damage. Any of these dice with values of 1 do not force you to take damage but still force the target to apply it.

Repair Systems

Assign any number of your ready crew to repair a ship’s system by moving that token onto the system slot on your roster. If the crew is still there at the start of your next turn, repairs will proceed as per the Resolve Ongoing Repairs step.

Damaging Systems

Whenever you are forced to take damage, select a system on your ship to take the damage and mark one of its empty checkboxes. Repeat this process for each point of damage inflicted.

While checkboxes on a system are marked, it is considered “damaged” and cannot be used for actions (such as attacking or healing), it contributes no Thrust, and cannot dissipate heat.

The following are true about damaging systems:

Losing Habitats

When a Habitat system is destroyed, immediately recalculate your Crew Complement. If the amount of crew tokens on your roster exceeds that new number, kill crew until the remaining tokens fit inside the complement.

Damaging Missile Systems

When missile systems that have not been depleted take damage, the ordinance in the missile rack explodes, forcing you to apply another 2 damage.

Time Limit

It’s entirely possible for you to end up with no working weapon systems and for a game to drag out forever. To keep the game from lasting forever and getting boring, we have a time limit.

If the game lasts longer than 10 minutes, the only actions you can take are:


Your ship is eliminated from the game if any of the following are true:


When all other ships are eliminated, you are victorious.

RPG Supplement Rules

When incorporating Cosmoforce into your RPG, you may replace any number crew tokens with characters from your RPG. Instead of tracking their ready and hurt status on the tokens, you’ll use your RPG’s native damage system to determine. Remember that space ship damage is a big deal so anything that would hurt crew in Cosmoforce should do your system’s equivalent of 50% of max damage to a normal character.

You may replace any one action taken on a turn with a “Crew Action” which can be any combat action normally taken by characters in your RPG’s native combat system.

GM fiat determines how the RPG’s action’s translate into Cosmoforce but some good ideas include…

GM’s are encouraged to be as generous as reason permits when interleaving the RPG system’s rules with Cosmoforce.

Ship Systems Chart

Here is a condensed summary of all ship systems in the game:

AfterburnerPropulsionFighterAdds +2 to ship's total Thrust
Armor Armor Any Absorbs damage up to Size Mod + 1
Dissipator DissipatorAny Radiates off heat every turn
Engine PropulsionAny Adds +1 to ship's total Thrust
Habitat Habitat Any Increases crew complement by Size Mod
Hangar Weapon CapitalAttacks w/1 die, triple damage if target's mass < 16
Laser Weapon Any Attacks w/1 die, hits impose heat, 7+ rolls backfire heat
Missile Weapon Any Attacks w/3 dice, a pair of 8's depletes
Railgun Weapon CruiserAttacks w/1 die or 3 dice if target is slower


Design by Anthony “Ishpeck” Tedjamulia.

Additional design by Sean Whetten and Jorey Dixon.


Copyright© 2018-2019 Mighty Pwnage Entertainment, LLC.

All rights reserved.