Still working on this, but I’ll post stuff piecemeal…

Ship Sizes and Classes

First things first: d20 starship sizes are redonkulous, so consider those scrapped. This isn’t crazy Death Star fantasy land; probably 90% of the ships in this or any other remotely hard sci-fi universe would never make it out of d20’s ultralight class.

On principle, I think a well-armed escort ship should not be in the same class as the fighters docked inside it. Likewise, a fat tramp freighter housing a couple dozen people should not be the same class as an actual fat tramp with a bunch of balloons tied to his lawn chair.

Anyway, enough ranting; here’s our much more sensible, commonly used, d20-friendly ship classification system…

Table: Starship Size

Size Size Starship’s
Class^1 Category Length
1 Fine less than 0.1m
2 Diminutive 0.1-0.3m
3 Tiny 0.31-0.6m
4 Small 0.61-1.2m
5 Medium-size 1.21-2.4m
6 Large 2.41-5m
7 Huge 5.1-10m
8 Gargantuan 10.1-20m
9 Colossal 20.1-50m
10 Ultralight 50.1-100m
11 Light 100.1-250m
12 Mediumweight 250.1-500m
13 Heavy 500.1-1,000m
14 Superheavy 1-2.5km
15 - 2.5-5km
16 - 5-10km
17 - 10-25km
18 - 25-50km
19 - 50-100km
20 - 100-250km

1 A smaller ship gains +2 size bonus per size class difference of the bigger ship

If it helps, you can basically ignore everything 9 and lower; we won’t really be in situations where it’s necessary to mix ship class and traditional d20 sizes. Just FYI: most of the (formerly ultralight) ships we’ll meet out on the edge of civilization will now be distributed between ultralight (i.e., fighters, shuttles), light (i.e., small freighters, some passenger transports), and mediumweight (big container freighters, armed cruisers) classes.

Starship Sheet Template

My not-quite-up-to-date Starship Sheet Template can be found here.

Starship Combat Mechanics, finally

Okay, here’s a first, rough whack a merged ruleset. Still lots to do, but should get us through a few encounters. Sorry for the formatting; running out of time.

One big change: Maneuvering and Firing split into separate steps. Ideally you want to move LAST, but SHOOT FIRST. Might not make sense at first, but I’ll explain for thoroughly when we get there.

A more cosmetic change, for realism: Starship Combat Rounds last 30 seconds (think Move Hald-Round 15 second, Fire Half-Round 15 seconds).

House rule: Facing rules of regular combat apply. +2 flanking attack bonus when shooting a ship’s predetermined weak side. Standard crossfire rules.

20 auto-hit, 1 auto-miss

Alternative Crit rules, with locational damage on ship

Damage multipliers (Crits, etc.): Can either roll damage multiple times or roll once and multiply number
Damage multipliers: But… some extra dice bonuses (i.e., Engineer’s Weap. Upgrade class abil.) never get multiplied

Initiating Combat

Every starship starts battle flat-footed (no Pilot Dex bonuses).

Determine Awareness if necessary: Sensor Op makes Computer Use check (Spot check out window as last resort).

Surprise round if any ships are not aware of all enemies.

Commanders roll opposing Starship Initiative checks (Knowledge [tactics] + INIT [using WIS not DEX]). They will continue to do this each round, so the Initiative will shift back and forth as the battle goes on.

Initiative winner Moves Second (for tactical advantage), Fires First for (not getting blown up advantage).

Note: Move Round and Firing Round count as A SINGLE ROUND for d20 purposes. Characters can do various actions in one or another, but they split their move/attack/free actions between the two Half-Rounds; they don’t get two separate sets of actions!

Move Half-Round: Moving, Turning, and Tactics
Fire Half-Round: Firing, Ramming, Grappling, Boarding, etc.


Moving, Turning, and Tactics

Commander and Crew work out strategy; players can move in any order.

Crew options:


The captain is the leader and coordinator, who directs the ship’s crew and coordinates their efforts. The captain is also responsible for determining the ship’s Initiative and sensing the enemy’s tactics.

> Single Full Round Action
> A captain caught in the confusion of battle can take a moment to simply observe. When a captain uses the re-focus action, he gets a +5 to the next round’s Initiative roll.
> Single Full Round Action
> A Knowledge (Tactics) check against a DC 15 allows the captain to coordinate the efforts of the gunners and pilots. This ability grants the ship a +1 morale bonus to Defense or Attacks, captain’s choice. This lasts until the captain acts again (even if that act is nothing).

> Single Move Action
> You attempt to assist a crew member doing some particularly vital task. Roll a DC 10 skill check or attack (matching—or sensibly synergizing with—the ally’s attempt). If you succeed, the ally gains a +2 circumstance bonus on his skill check. Aiding someone in a different part of the ship makes this a Standard Action.


The pilot or helmsman is the individual responsible for actually moving the ship in space. The pilot determines how hard the ship is to hit.

> Single Move action, moving up to ship’s speed (at least until I get acceleration rules worked out). If ship moves, it cannot also shift during the same turn.

d20 Future p. 143

> d20 Future p. 116

> Single Standard Action
> Attack action. A Bluff check (opposed by enemy’s Sense Motive check) misleads another starship so that it can’t Dodge as effectively. If successful, next attack ignores enemy pilot’s DEX bonus to Defense. Doesn’t work against auto-pilot. Starship Feint feat gives +2 to these Bluff checks.

> Single Standard Action
> DC 15 Pilot check. Complex evasive maneuvers. Ship gets +4 Dodge bonus to Defense for 1 round. If used before ship movement, it applies to any opposing Attacks of Opportunity made during the same round. During this wild maneuvering, Gunners may not fire their weapons.

> Single Standard Action
> DC 10 Pilot Check. Fancy ship maneuvering the ship a +2 Dodge bonus to Defense for 1 round. Gunners may fire, but the maneuvering gives them a -4 penalty to all attacks.

> ??? JINK (Just an alt. Defensive Fighting move until I get it fixed)
> Single Standard Action
> A Pilot can move his ship erratically, making it more difficult to hit. To do so, he must make a Pilot check (DC 10). The size of the ship imposes a penalty on the Pilot check (Ultralight -0, Light -2, Mediumweight -4, Heavy -8, Superheavy -16). The ship gains a +2 dodge bonus to Defense if the pilot succeeds, with an additional +1 for every 5 points by which the pilot beat the DC. The bonus is doubled and applied as a penalty to any attack rolls that may overlap with the jinking, with the exception of missiles. Effect lasts until the beginning of the next round. [Yes I know this is a slightly more luck-based version of Defensive Fighting; I’ll work on it.]
> No Action
A sideswipe is a maneuver in which a pilot attacks with the ship directly, causing an indirect collision. This preliminary step isn’t an action in itself, but I’m mentioning it here to remind Pilots that they need to occupy an enemy ship’s space in order to attempt a Sideswipe or Ram maneuver during the Firing Round. So use your standard tactical maneuvering to do that, taking an AoO if the enemy ship has a Point Defense System.

> No Action
> Like Sideswipe, a Ram is an intentional collision. Unlike a Sideswipe, it is a direct strike. Without the proper equipment a Ram is suicidal, as both ships will take massive damage. This is not a move; it’s really just a reminder for Pilots. The actual Ramming move is taken in the Firing Round, but, like Sideswipe, you’ll need to maneuver yourself into an enemy’s space before making the attempt. Use standard tactical maneuvering to do so. Standard Point Defense System AoOs apply when moving into an enemy’s space.

> … (requires afterburners)

> Single Full Round Action
> Starship can move at twice its tactical speed, and it’s starting space does not count as threatened (i.e., ship takes no AoOs when it leaves that first hex).

> Single Full Round Action
> A difficult and dangerous maneuver, it is effective for shaking off close pursuit. By making a DC 20 Pilot check, along with the engineer’s DC 20 Repair check, the pilot spins the ship 180 degrees, passes the ship directly under the pursuing ship, and immediately initiates a full-burn of the engine, causing a concussive force. The enemy ship must make a Reflex Save (DC 15) or be stunned for 1 full round (both Movement and Firing).
> Note: this maneuver can only be performed if the enemy is behind the pilot’s ship and within one move action.
> A failure on the Pilot check causes a sideswipe to occur during the pass, and prevents the concussion blast. If the engineer fails the Repair check, the ship spins around but the engine chokes, stalling the ship in place. If both checks fail, the ship is stunned, negating all ship-related actions until the pilot and engineer act to set things straight. Required: 5 Pilot skill (10?)


> Single Move Action
> In the course of his duties, the Co-Pilot regularly makes Aid Action (DC 10 Pilot check) attempts to lend a +2 circumstance bonus to the Pilot’s Pilot rolls. The Co-Pilot’s Pilot assists count as a Move Action, leaving him an Attack Action to do something else. On smaller ships, a Co-pilot might also serve as a Gunner or Sensor Operator.

> Single Move Action
> In addition to helping the Pilot with a Move Action, you may attempt to assist another crew member in his task with an Attack Action. Roll a DC 10 skill check or attack (matching—or sensibly synergizing with—the ally’s attempt). If you succeed, the ally gains a +2 circumstance bonus on his skill check. Aiding someone in a different part of the ship makes this a Standard Action.

Com Officer / Sensor Operator

> Single Move Action
> The Com Officer can attempt an Aid Action (DC 10 Pilot check) to lend a +2 circumstance bonus to the Pilot’s next Pilot roll.

> Single Move Action
> A Sensor Operator may choose to focus on monitoring the enemy, analyzing heat signatures and subtle changes in the ship’s energy to help discern what they are planning to do next. Alert grants the user’s ship a +1 bonus to Defense if he or she succeeds on a DC 15 Computer Use check. This lasts until the sensor operator acts again.

> Single Move Action
> The ships sensors can be synced with a Gunner’s targeting computer, allowing the two to share data and greatly increasing the targeting computer’s effectiveness. An assisting sensor operator grants all gunners a +1 bonus on their attack rolls until he or she acts again.

> Single Standard Action
> By staying on the Com, and walking the Gunner through his firing solutions, the Sensor Officer can attempt an Aid Action (attack against DC 10 Defense) to lend a +2 circumstance bonus to the Gunner’s next attack roll, even though they’re likely on opposite sides of the ship.

> Single Standard Action
> Using the communications system, a Sensor Operator may send out meaningless data that nevertheless is picked up and processed by a ship’s communications array, clogging it and preventing it from sending or receiving data. A Computer Use check (DC 15) is required to jam the signal at all, and the result of a successful check becomes the DC that the enemy ship must beat to overcome the jamming. This lasts for one round, but can be renewed by a standard action with no break in the interference. Overcoming being jammed is itself a Standard action.

> Single Full Round Action
> You can create an array of strange energy emissions that enemy sensors can detect, with a Computer Use check (DC 15). These false readings are difficult to sort through, and cause the enemy ship to lose the bonus granted by its targeting computer, as well as any assist bonus from its own sensor operator. This lasts for one round. To overcome the jamming, the enemy sensor operator must succeed at a Computer Use check, with a DC of the original check to jam. This requires a Standard Action.


> Single Move Action
> If ship is equipped with a damage control system, Engineer can perform Damage Control as a move action. Most Damage Control Systems require DC 15 Repair check to restore a certain amount of HP/SI.

NOTE: Specifics on d20 Future p. 134

Single Full Round Action
The Engineer can repair minor damage to system during combat. Take a Repair check, DC dependant on complexity of problem. System must not be destroyed or have suffered catastrophic damage.

> Single Standard Action
> Typically, only expensive military have shields. In a ship with shields, though, the Engineer can tweak the power distribution to move a ship’s “weak side” according to the needs of combat. Restoring the shields to normal is itself an action.

> Sorry, mechanic not in place yet. You’ll be able to sacrifice one system’s functionality to lend a bonus to another (i.e., Power down the Point Defense System; divert that power to strengthen the Shield)






Firing, Ramming, Grappling, Boarding, etc.



> Single Move Action
A sideswipe is a maneuver in which a pilot attacks with the ship directly, causing an indirect collision. If the Pilot has already maneuvered the ship into an enemy ship’s space, he may attempt this maneuver. Pilots make an opposed Pilot check. If the attacker wins, both ships take damage as in a collision, with a multiplier of 1/4. The defender may make a Reflex Save (DC 15) to cut the damage both ships take in half.

> No action
>> Like Sideswipe, a Ram is an intentional collision. Unlike a Sideswipe, it is a direct strike. Without the proper equipment a Ram is suicidal, as both ships will take massive damage. To attempt this maneuver, both ships must be occupying the same space. Pilots make an opposed Pilot check (Defender get a bonus of 5+1d4). If the attacker succeeds, the ram is head-on, and the collision multiplier is 1. If the defender succeeds, the ram instead degrades into a sideswipe. In either case, the defender may make a Reflex Save (DC 15) to reduce the damage both ships take by half.

NOTE: Collision Damage is 6d6x10 if smallest ship is standard ultralight; if smaller ship is Light or larger, both ships take 12d6x10 damage. For sideswipe damage, roll all dice and quarter the result.

d20 Future p. 143



> ATTACK (Ranged)
> Single Standard Action. Fires a single, fire-linked set, or bay of weapons. Gunner must be at appropriate gunnery station.

> Single Standard Action
> Instead of acting to damage the enemy, a gunner can scare an enemy back with strategic patterns of fire. The ship gains a +2 bonus to Defense against attacks from any direction in which the weapon can fire on the turn or turns on which it fires. Cover fire can only be performed with a ship’s main guns, turrets, or batteries, and consumes as much power as firing the weapon in a normal attack.



Trades of Terra Norma trustywren