Space Combat

The clash of ships in the void, the flash of silent explosions and soundless death... these things are familiar to interstellar adventurers, and a natural hazard of the profession. While most adventurers seek to avoid such hull-melting conflagrations of war, sometimes the choice is not their own. When two or more ships close to combat range with the intent to kill, it’s time to fight.

The combat round

Ship combat begins with a a group initiative roll between the dueling ships. Once every ship has had a turn, the round starts over from the top. On its turn, a ship’s captain decides in which order its various systems will act: pilot, weapons, engineering, comms, and shields. The player or NPC controlling each system can choose their actions based on the amount of ship energy points remaining. Some actions generate energy points, but most deplete them. Once a ship has used their energy points (or chooses not to spend anymore) the next ship goes. Energy points do not carry over to the next round. Unspent Energy Points can be used for reactions however, so it can make sense to bank some points for that.

Ship systems

For the purposes of interstellar combat, each system is ideally controlled by one or more crew, but crew can double up on systems with the assistance of artificial intelligence if necessary. If a character has training in the system, they can add their proficiency bonus to rolls made using the system. Most characters will only have training in one system. The Pilot system is responsible for the ship’s movement and navigation, and handles attempts to pursue or escape combat and evasive maneuvers. The comms system is responsible not just for inter-ship communication but also electronic warfare, including disabling enemy systems, gleaning information about their defenses, and disrupting the systems of enemy ships. The weapons system is responsible for handling the ship's weapons, making targeting calculations and taking attacks against opposing ships and crew. The shield system is responsible for deflecting or reducing the amount of damage taken from attacks, as well as maintaining oxygen seals and the ship's artificial gravity. The engineering system is responsible for repairing damage to the ship's hull and generating energy points for the other ship systems.

Actions and Energy Points

At the start of each ship's turn, the captain decides the order of each system. When a system's turn comes up, the player(s) commanding that system chooses actions, either from their system list or the generally allowed combat actions in 5e. A player can take as many actions as they have Energy Points to spend on them. A weapons commander with 4 Energy Points, for example, could fire a weapon once spending a couple energy points, or they could use all remaining energy points to unload on a ship. The system commander does not need to get permission to spend points from the rest of the crew; if they decide to burn the points to open fire when the rest of the crew wanted them to save them, that’s too bad for the rest of the crew. A traitorous or uncooperative system commander can only be stopped by PC intervention.

Hacking

Electronic warfare is a major element to space combat. When attempting to hack during combat, it's likely the other ship is anticipating it and so most hack attempts are made via a contested skill check. When a system crashes, the GM rolls on the Crash table to find out what the result of the crash is. Systems are usually still usable in a crashed state, but with unknown effects. It costs three Energy point to restart a crashed system, and is automatically successful. Alternatively crashed systems will automatically rapier themselves after three rounds.

Repairing Damage

The engineer is capable of repairing damage to the hull by deploying EERB's (External Emergency Repair Bots). In addition to repairs, they can boost the power of the ship's thrusters.

Disengaging

A ship can disengage with combat in two ways. First, a ship has disengaged from combat if they have moved 50 or more units from enemy ships. A ship can also disengage by using the Escape Combat action to gain Escape Points. Once a ship amasses three Escape Points it gets away and is no longer in combat. The Pursue Target action can be used to dock Escape Points from ships.

Crises

Instead of taking a particularly brutal hit or damage, the captain can instead choose to accept a Crisis. The attack is then negated with no damage done. Instead, the GM rolls on the Crisis table to find out what dire event happened as a consequence of the hit, instead of the ship damage.

Some of these Crises are continuing. They will continue to plague the ship until a player can solve them using an Action or combination of Actions. Some of these Crises are acute. The players must solve them before the end of the ship’s next turn or else something very bad will happen. A ship can accept only one Crisis per round. Thus, if the ship is hit twice, only one of those hits can be converted into a Crisis. A ship accepts a Crisis if any of the department heads requests it, even if the rest of the heads don’t want one. Thus, if the ship’s main gun is hit, the gunnery chief can request a Crisis to prevent the hit even if the rest of the crew was against it.

To resolve a Crisis, a player needs to expend an action on their department turn. They must explain what they are doing to solve the problem to the GM, who will then tell them what combination of attribute and skill they should roll. The usual diffi- culty of resolving a crisis is 10, though the GM may increase or decrease that difficulty by up to 2 points either way depending on how bad the Crisis is and how useful the PC’s plan is to resolve it. If the PC succeeds in the roll, the Crisis is ended. Continuing Crises no longer apply their penalty to the ship, and acute Crises are defused before disaster can strike. If they fail, a continuing Crisis is unchanged and an acute one is yet unresolved. More than one PC can try to resolve a Crisis, either making an independent attempt if they have a relevant skill, or using their talents to aid the main responder with the usual rules for aiding another’s skill check.

The Deal with a Crisis general action can also be used to get a scene’s worth of general activity aboard the ship. If a robot suddenly breaches the ship’s hull during a battle, two of the PCs might take an action to spend a scene battling the robot in the guts of the ship while the rest of the party tries to keep the ship fighting.

Ship Combat Actions

Captain Actions

Support System (0 EP): Once per round, the captain can support one system. One action taken at this system takes 2 fewer energy points.

Accept Crisis (0 EP): The captain can choose to accept a crisis instead of receiving damage from an attack. There can only be one ongoing crisis at a time.

Pilot Actions

Fly (0 EP): The ship may fly up to their movement speed. Normal flight is not capable of disengaging from combat unless the ship moves 50 units from enemy combatants.

Dodge Incoming Attack (1 EP per use, reaction): Roll a D20 + proficiency if applicable and apply the modifier to reduce the damage your ship takes from an incoming attack. On a critical fail, the damage increases by +5. <5: +2, < 10: +1, 10 - 14 = +0, > 15: - 3, > 20: -6

Evasive Maneuvers (2 EP): Deploy evasive maneuvers. This gives disadvantage to attacks made against your ship for the next turn, but it also gives disadvantage to weapon attacks made by your own ship for the next turn.

Escape Combat (3 EP): Make a contested skill check against the fastest enemy ship in combat. On a success, your ship gains one Escape Point.

Chase Target (4 EP): Make a contested skill check against an enemy ship. On a success, the enemy ship loses one Escape Point.

Shield Actions

Deflect Attack (1 EP per use, reaction): Roll a d20 + proficiency. If your roll is greater than the attack roll, the attack misses.

Overclock Shield (2 EP): Roll a D20 + proficiency if applicable and apply the modifier to your ship's AC for the next turn. On a critical fail -5 to the ships AC. <5: -2 AC, < 10: -1 AC, 10 - 14 = +0 AC, > 15: + 3 AC, > 20: +6 AC

EMP Obstruct: (4 EP): Deploy an EMP obstruction device. Inside a 10 unit radius centered on where you deployed the device, your ship has gained the effects of the Mirror Image spell.

Comms Actions

Reenforce Firewall (1 EP per use, reaction): Reenforce the ship's firewall using an AI agent to strengthen defenses. As a reaction when an enemy ship attempts to hack your ship, roll a d20+proficiency and add the modifier below to your contested roll. You must expend the energy point before your roll, but you may do so after the enemy's roll. On a critical fail, -5 to the modifier of the roll. <5: -2 , <10: -1 ,10 - 14 = + 0, > 15: +3 , > 20: +6

Crash System (3 EP): Attempt to induce a buffer overflow on an opposing ship's system. Make a contested roll: on a success, the targeted system crashes.

Restart System (4 EP): Restart a crashed system.

Weapon Actions

Targeted Attack (1 EP): Roll a D20 + proficiency if applicable and apply the modifier to increase the damage your ship does to its next attack. On a critical fail, the damage decreases by -5. <5: -2, < 10: -1, 10 -14 = + 0, > 15: + 3, > 20: +6

Mag Dump (2 EP): When attacking with a ship's weapon, make an additional attack with the same weapon against the same target. Attackers will have advantage against your ship on the following turn.

Ion Cannon (2 EP): Saving Throw DC 8 + ability modifier + Proficiency if proficient with weapons (on a failed save 2d8 damage half on a success)

Rail Gun (3 EP): Attack roll D20 + ability modifier + proficiency if proficient with weapons (on a hit 3d10 damage)

Engineering Actions

Overclock Generator (1 EP): The engineer can attempt to overclock the ship's generator, producing more energy points. Make a d20+Proficiency check and add or subtract the resulting energy points to the remainder of the turn. On a critical failure, the ship's energy points are halved for the next round. On a critical fail, the -5 to to the ships EP for the round. <5: -2 EP, < 10: -1EP, 10 -14 = + 0 EP, > 15: + 3 EP, > 20: +6 EP

Boost Engines (3 EP): Boost power to the ship’s engines, providing an additional 5 squares of movement for the turn. If the ship also takes the Escape Combat or Pursue Target Action, it doubles a success on those turns.

Emergency Repairs (4 EP): Deploy EERB's to fix major damage to the external hull of the ship. Roll a d8 + your proficiency if you have proficiency, and the ship regains that many hit points.