A space combat mini-game and RPG supplement.
Why should you care?
You want this game if…
- You want to build and blow up space ships
- You want to staple space combat onto your RPG
- You want to replace your RPG’s hyper-complicated space ship system with a leaner one
- You want a happy medium between hard science fiction and fun game-play
- You are obsessed with D8’s and think they should get more use
How’s it Play?
This game has two major aspects:
- Building ships
- Strategic attrition
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!
To play Cosmoforce, you’ll need:
- Eight-sided dice (about a dozen of them)
- Coins representing “Heat Tokens”
- Different coins representing “Crew Tokens”
- A Roster Sheet for each player
- Paper, pencils, and this document
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||1||A small, nimble vessele|
|Cruiser||2||Medium weight gun-ship|
|Capital Ship||3||Massive, 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||Thick plates of metal and ceramic to protect your ship|
|Dissipator||Sheets of thin metal with lots of surface area to radiate heat|
|Engine||Nozzles that focus bursts of energy to propel your ship|
|Habitat||Enclosed structures with CO2 scrubbers, food and medicine|
|Laser||High powered beam weapon that cooks enemy ships|
|Missile||A weapon full of self-propelled warheads to blast enemy ships|
In addition to these, each class of ship has a special system that only it can mount. These systems are…
|Afterburner||Fighter||An enhanced, compact engine system|
|Hangar||Capital||Holds tiny drone fighters to swarm enemies|
|Railgun||Cruiser||High powered cannon to punch holes in stuff|
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…
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.
Note: Having 10 habitats is not recommended.
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.
If the crew is ever harmed, flip the token over to the “tails” position to denote that they are hurt.
If hurt crew are harmed, they are 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…
Speed is the general term referring both to your ship’s velocity and its maneuverability.
Your ship will begin the game with a speed equal to the cumualitve thrust contributed by all its 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
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.
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.
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.
Each turn involves the following steps executed in the following order:
- Resolve Ongoing Repairs
- Manage Heat
- Check for Collisions
- Take Actions
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 onto the Standby box, or leave it there to continue repairs.
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
If your ship has 0 total Thrust (because it does not have any propulsion systems or because all its propulsion systems are damaged), your ship is drifting aimlessly in space and is at risk of colliding with space debris.
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.
You are allowed to take two actions on your turn. They can be any of the following:
- Burn Engines
- Heal Crew
- Repair Systems
Select another ship and a type of weapon system mounted on your ship. You may use any number of your 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.
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 are the go-to weapon for anybody looking to obliterate things in a hurry. Their on-board targeting systems and high yield explosive can shred anything with ease. Just be careful to not damage missile systems before you deplete them because their destructive payload can turn against you.
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 circling the word “Depleted” on its slot. Depleted missiles can not be used for the rest of the game.
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.
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.
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.
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 take the Burn Engines action in order to evade. If the ship does not evade or if your speed is higher than the target’s after the evasion attempt, your two ships collide.
When your ship collides into the target, roll a die for each whole point of speed your ship has. Each effective die forces the target to apply 1 damage and each such die with an even value forces you to apply 1 damage to your ship as well.
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.
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 damage 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:
- Armor is destroyed when it suffers damage equal to
Size Mod + 1.
- All other systems are destroyed when they suffer 2 damage.
- Damaged systems can be repaired but destroyed systems can not.
- Crew assigned to repair a system while it takes damage become hurt and are removed from that slot assignment
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.
After a missile system is depleted, applying damage to it has no negative effect.
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:
- Burn Engines
Your ship is eliminated from the game if any of the following are true:
- All your crew are killed
- All your ship’s systems are damaged
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…
- Magical effects that involve freezing or cold can be used to remove heat tokens
- Character capabilities that involve fixing things could be used to repair systems more quickly
- Healing effects could flip hurt crew over to ready
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:
|Afterburner||Propulsion||Fighter||Adds +2 to ship's total Thrust|
|Armor||Armor||Any||Absorbs damage up to Size Mod + 1|
|Dissipator||Dissipator||Any||Radiates off heat every turn|
|Engine||Propulsion||Any||Adds +1 to ship's total Thrust|
|Habitat||Habitat||Any||Increases crew complement by Size Mod|
|Hangar||Weapon||Capital||Attacks 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||Cruiser||Attacks w/1 die or 3 dice if target is slower|
Design by Anthony “Ishpeck” Tedjamulia.
Additional design by Sean Whetten and Jorey Dixon.
- Adam Leavitt
- Anthony Sutton
- Gabe Glaser
- Jefferson Albright
- Jennifer Tedjamulia
- Jonathan Albright
- Pradeep Beri