#crystalspheres

Alright, listen up, fellow DMs and players! You know how much we all love Spelljammer, right? The idea of magic ships sailing through space? Pure gold. But let's be honest, the 5e rules for actually doing that sometimes feel a little... thin. We've all been there, trying to make sense of ship combat that just kinda boils down to "get close and board." Not exactly the epic space battles we dream of.

So, I've been tinkering. A lot. I've dug deep into the old 2nd Edition AD&D Spelljammer stuff – the real classic material, the stuff that came out long before things like The Mending or the Spellplague messed with the cosmos. That lore? It's solid, and it's untouched by all that later chaos, which is fantastic for building a consistent universe. Then, I looked at how other awesome games handle tactical combat, especially Pathfinder 2e's ship rules, which are just chef's kiss for making every decision matter.

What you're about to read is my take on how to make spelljamming in 5.5e (the 2024 version, you know the drill) feel truly epic. We're bringing back that tactical depth, making crew roles feel important, and really leaning into the wild, weird, and wonderful cosmology of the original setting. This isn't just about moving numbers around; it's about making you feel like you're commanding a ship through the stars.

The Cosmos of Spelljammer: A Quick Refresher (and Some Old-School Lore!)

First off, let's get our bearings in this wild universe. You know the multiverse is huge, but a lot of the familiar D&D worlds are actually tucked inside these giant, invisible, crystalline bubbles called Crystal Spheres. Each one's basically its own little solar system – sun, planets, moons, asteroids, all doing their thing inside this cosmic shell. Pretty neat, huh?

Now, step outside one of those spheres, and that's where things get really interesting. You're in the Flow. Think of it as this incredibly vibrant, turbulent, rainbow-colored ocean of pure, flammable magic. Old-timers called it the Phlogiston, and yeah, that's still what it is. It's the cosmic river that connects all the Crystal Spheres, letting us zip between entire campaign settings. But be warned: it's not just pretty. The Flow's got currents, eddies, and even its own weird, dangerous critters. And here's a big one: if you go throwing fire spells around in the Flow (like a Fireball or even a dragon's fiery breath), you're gonna have a bad time. This stuff is highly flammable, and you could ignite the whole area, turning your ship into a very expensive, very fast-burning bonfire. Trust me, you don't want that.

Inside a Crystal Sphere, between the planets, that's Wildspace. It's the vacuum we're more familiar with, full of stars, planets, and sometimes, truly bizarre creatures. Wildspace has its own rules for gravity and air, different from the Flow. It's where most of your ship-to-ship battles are gonna happen.

The Essentials of Spelljamming: How Your Ship Actually Works

At its core, getting a spelljamming ship to move comes down to three big things: the Helm (that magical seat you sit in), the different Modes of Travel (because space isn't just one speed), and the super important Gravity and Air Envelopes that keep you alive out there.

Your Helm: The Engine of Magic

Every spelljamming vessel needs a Spelljamming Helm. This isn't just a fancy chair; it's the magical heart of your ship, turning raw magical energy into propulsion.

Attunement: Someone's gotta be attuned to it, just like any other magic item. Simple enough.

Piloting: The person attuned to it, usually a spellcaster, becomes the Pilot. They use their action each round to literally will the ship to move. It costs them a spell slot (or you can use "Helm Points" for a more detailed system, if your DM's feeling spicy) to keep the helm going for a set amount of time – like, 8 hours per spell slot level.

Magic Drain: Here's the kicker: while you're piloting, you can't cast any other spells. All your magical oomph is going straight into that ship. So, choose your Pilot wisely!

Two Ways to Travel: Slow & Steady vs. Warp Speed!

Your spelljammer has two main gears, depending on where you are and how far you're going.

Wildspace Speed (Tactical/Local Travel): This is your everyday cruising speed. It's for when you're fighting, sneaking around an asteroid field, or just puttering between planets in a solar system. We measure this in feet per round. It's way faster than walking, but it's a snail's pace compared to...

Flow Speed (Interstellar/Long Distance Travel): This is how you cross the vast, mind-boggling distances between Crystal Spheres. When you're in the Flow, time kinda blurs, and travel is measured in days or even weeks. It's super fast, but it's also super dangerous, and you'll need a good Navigator to keep you from getting lost (or worse!).

Gravity and Air: Your Life Support System

This is where some of that classic 2nd Edition lore really shines, and it's essential for survival out in the void.

Gravity Planes: Every spelljamming ship creates its own little bubble of gravity. It's a flat plane, usually running along the deck, that lets everyone stand normally. This means you can have ships with decks on the "top" and "bottom," with people walking around on both simultaneously! Gravity extends a bit beyond the hull, too, so you don't just float off if you step off the side.

Air Envelopes: This is big. Your ship carries its own bubble of breathable air, sized for the vessel and its crew. It's like a giant, magical, self-contained atmosphere.

Duration: This air isn't infinite! It lasts for a set time, say, a month for every 50 tons of ship, assuming you've got the right number of crew. If you cram too many people on board, that air runs out faster.

Stale Air: After about half its normal duration, the air gets "stale." Everyone on board starts getting disadvantage on Constitution saving throws against things like diseases, exhaustion, or anything that messes with your breathing. It's not deadly yet, but it's a warning.

Fouled Air: When that air duration finally runs out, it's "fouled." Now you're in trouble. Everyone on board starts suffocating, just like if they were holding their breath underwater.

Refreshing Air: How do you get fresh air? Easy! Fly through a planet's atmosphere, dock at a big space station with air scrubbers, or sometimes, you'll find magical anomalies that just refresh your supply. The cool thing is, this air envelope keeps the nasty Flow stuff out, so you're breathing good, clean air even in the middle of that rainbow soup.

Ship Combat: It's a Team Effort!

Forget individual turns for everyone; in ship combat, your crew works as one, making the ship itself a character. This whole system is inspired by the awesome tactical feel of Pathfinder 2e's ship combat, adapted for our 5e.5 rules.

Who Goes When?

Ships have their own initiative!

Initiative Roll: At the start of a fight, your Pilot (or whoever's calling the shots, the Captain) rolls initiative for the ship. They use their Dexterity modifier plus the ship's Maneuverability Bonus (MB). Highest roll goes first!

Crew Action Phase: When it's your ship's turn, the crew takes actions. Nobody's got their own separate turn here; everyone's contributing to the ship's overall action pool.

Ship Action Phase: After all your crew members have declared and resolved their actions, the ship actually moves and its weapons fire, based on how well your crew did.

Crew Actions: Your Ship's Fuel

Your ship gets a pool of Crew Actions. How many? Usually, it's equal to the number of active crew members you have assigned to roles. Smaller ships might have a minimum (like 3 actions), and bigger ships might get more for extra crew.

Action Cost: Every single thing a crew member tries to do costs one of these Crew Actions.

Key Roles: Your Pilot, Captain, Chief Gunner, and Engineer are your heavy-hitters. They can usually use a set number of the ship's Crew Actions per turn (say, 2 or 3 each), 'cause their jobs are demanding. Deckhands and general crew usually contribute single actions or help others.

Doing Too Much? Disadvantage! This is a big one, inspired by Pathfinder 2e's "Multiple Attack Penalty" but using our familiar 5e Disadvantage. If a crew member tries to do two or more actions of the same type in a single turn (like a Gunner firing two different weapons, or an Engineer trying two repairs), that second action (and any after it) is made with disadvantage. It makes you think about whether it's worth pushing your crew too hard!

What Your Crew Can Do: Roles & Responsibilities

Here's a breakdown of what each key role on your ship can do, and how those actions play out. Remember, we're using those "degrees of success" here – not just pass/fail, but critical success and critical failure too!

Captain (Leadership & Tactics)

The Captain's the boss, the one who keeps everyone focused and makes the big calls.

Command (1-3 Crew Actions): You bark orders, inspiring a specific crew member. Pick someone, and they get a bonus to their check this turn (like +2 to the Pilot's maneuver, or +1 to a Gunner's attack). You make a Charisma (Persuasion or Intimidation) check.

Success: They get the bonus. Nice!

Critical Success (Roll 10+ over DC): You're a natural leader! The bonus is bigger (maybe +4!), or you can give it to a couple of crew members.

Failure: No bonus. Awkward silence.

Critical Failure (Roll 10+ under DC or Natural 1): You messed up the order. That crew member (or maybe everyone!) gets a penalty (-2) to their checks this turn. Oops.

Inspire/Rally (2 Crew Actions): You give a rousing speech, or just a firm nod. All crew members get some temporary hit points (like 1d4 + your Charisma mod), or you can snap up to three crew members out of a fear condition. Requires a Charisma (Performance) check (DC 13).

Direct Fire (1 Crew Action): You spot a weakness! Pick a target, and one of your gunners gets advantage on their attack roll against it this turn.

Brace for Impact (1 Crew Action): "Brace! Brace! Brace!" You yell. Your ship's AC or Damage Threshold (more on that in a sec) goes up by 2 against the next attack this round.

Pilot (Helm & Navigation)

The Pilot is literally steering the ship, making all the big moves. This is a high-pressure job!

Maneuver (2-3 Crew Actions): This is your main move. You make a Dexterity (Vehicles (Air/Space)) check against a DC based on how tricky the maneuver is and your ship's Maneuverability Rating (MR).

Success: Your ship moves its full Speed and turns like normal (see "Ship Movement"). Smooth sailing!

Critical Success (Roll 10+ over DC): You're a master! Your ship moves its full Speed, turns even better (like 60 degrees per MP!), AND you either get advantage on your next attack or impose disadvantage on attacks against your ship until your next turn.

Failure: You fumbled. Your ship moves at half speed and can't turn more than 45 degrees this turn.

Critical Failure (Roll 10+ under DC or Natural 1): You lost control! Your ship spins off in a random direction (roll a d8 for a compass direction, or DM picks), maybe crashes into something, taking damage (1d6 bludgeoning per 10 feet of remaining movement), and the Helm becomes Disabled (Minor) until an Engineer fixes it.

Ram (3 Crew Actions): "Full speed ahead!" You try to smash into an enemy ship. This is a contested Dexterity (Vehicles (Air/Space)) check against their Pilot.

Success: Both ships take damage based on their size and how fast you were going (DM decides dice, like 4d6 to 10d6).

Critical Success: You hit 'em hard! Your ship deals maximum damage to the target and disables one of their major systems (Helm, Engine, Main Mast – DM's choice) with a Disabled (Major) condition. You only take half damage yourself.

Failure: Both ships take half damage. It was a glancing blow.

Critical Failure: You missed badly! Your ship takes full damage, deals nothing to them, and your own Helm becomes Disabled (Minor).

Grapple (2 Crew Actions): You want to get close for boarding! Make a Strength (Athletics) check contested by the enemy pilot's Dexterity (Vehicles (Air/Space)) check.

Success: You're hooked! The ships are grappled together, ready for boarding.

Failure: You couldn't get a good hold. No effect.

Critical Failure: You left yourself wide open! Attacks against your ship have advantage until your next turn.

Gunner (Weapons & Ballistics)

These are your sharpshooters, manning the big guns!

Fire Weapon (1-2 Crew Actions): You aim and fire one of your ship's mounted weapons. Make a Dexterity (Tools (Artillerist's) or appropriate weapon proficiency) check against the target ship's AC.

Remember the Disadvantage! If you try to fire a second weapon this turn, that second attack roll is made with disadvantage.

Success: You hit! Deal the weapon's damage.

Critical Success (Roll 10+ over AC): Boom! You scored a critical hit! Deal double the weapon's damage dice, or trigger a special critical effect listed in the weapon's stat block (like disabling a system, piercing armor, or setting them on fire!).

Failure: You missed. Whiff.

Critical Failure (Roll 10+ under AC or Natural 1): The weapon misfired! It can't fire next turn, or it's jammed and needs an Engineer to fix it.

Aim (1 Crew Action): You take a little extra time to line up your shot, giving a +2 bonus to your next Fire Weapon action this turn.

Reload (1 Crew Action): Some weapons need reloading. This action reloads one weapon with the "Loading" property.

Engineer (Repairs & Systems)

Your Engineers are the unsung heroes, keeping the ship from falling apart around you!

Repair System (2 Crew Actions): You try to fix up the ship, restoring hit points or repairing a broken component. Make an Intelligence (Tools (Carpenter's, Smith's, or Tinkerer's)) check.

Remember the Disadvantage! If you try a second repair action this turn, that second check is made with disadvantage.

Success: You patched it up! Restore 1d6 HP to a damaged section, OR remove one Disabled (Minor) condition from a system.

Critical Success (Roll 10+ over DC): You're a miracle worker! Restore 2d6 HP, OR remove one Disabled (Major) condition from a big system (Helm, Engine, etc.).

Failure: You couldn't quite fix it. No effect.

Critical Failure (Roll 10+ under DC or Natural 1): You made it worse! The section takes 1d4 damage, or another system becomes Disabled (Minor).

Boost Power (2 Crew Actions): You can temporarily supercharge a system. Make an Intelligence (Tools (Tinkerer's)) check (DC 13). If you succeed, you could give a weapon a temporary +1 to attack, or boost the ship's speed by +5 ft until your next turn.

Douse Fire (1 Crew Action): "Fire on deck!" You grab a bucket or an extinguisher and try to put out a blaze. Make a Wisdom (Survival) or Strength (Athletics) check (DC 10).

Deckhand/Sailor (General Support)

These are your general crew, making everything else run smoothly.

Assist (1 Crew Action): You lend a hand to another crew member, giving them advantage on their next check this turn. You have to declare this before they roll their dice!

Movement (1 Crew Action): You zip between stations, moving up to double your normal speed on deck.

Boarding Action (1 Crew Action): You get ready to storm the enemy ship! If you successfully grapple, your first attack roll when boarding gets advantage.

Ship Stat Blocks: What to Look For

When you're looking at a ship's stats, here's what all those numbers mean:

Hit Points (HP): How much punishment the ship can take before it's toast. These are way higher than character HP!

Damage Threshold (DT): This is important! Any damage that's less than the DT just bounces off or causes superficial scrapes (like Pathfinder 2e's "Hardness"). Only damage that meets or exceeds the DT actually chips away at the ship's HP.

Armor Class (AC): How hard it is to actually hit the ship. It's based on its size, any armor it has, and how well the Pilot is maneuvering.

Speed: How fast the ship moves in Wildspace, in feet per round.

Maneuverability Rating (MR): This is a static number (0-5, 5 being super agile, 0 being a brick). It tells you how nimble the ship is.

Maneuverability Bonus (MB): This is derived from the MR (e.g., MR 5 gives a +5, MR 0 gives a -2). Your Pilot adds this to their Dexterity (Vehicles) checks when they're trying to pull off fancy moves.

Crew Capacity: How many crew you need (minimum, optimal, maximum). Too few, and you'll be struggling; too many, and your air runs out faster!

Weapons: All the big guns! They'll have their own attack bonus, damage dice, any special critical effects, and properties like "Loading" or their "Firing Arc" (Front, Side, Rear).

Air Duration: How long that air envelope lasts for your optimal crew. Keep an eye on this!

Special Abilities/Immunities/Vulnerabilities: Any unique quirks, resistances, or weak spots the ship might have.

Ship Status Conditions: When Things Go Wrong

Ships don't just lose HP; they can get messed up in specific ways, just like a character can get poisoned or grappled. These conditions are inspired by Pathfinder 2e's detailed damage system.

Disabled (Minor/Major): A specific system is broken or impaired. Minor means it's still usable but with disadvantage on related checks. Major means it's completely out of commission. An Engineer needs to fix this!

Breached: Uh oh, a hole in the hull! Air (or water, if you're in an atmosphere) is leaking out. In Wildspace, your crew will start suffocating after a while if it's not sealed up. Get an Engineer on it, stat!

Burning: Your ship's on fire! It takes ongoing fire damage every turn, and the fire can spread. You need an Engineer to douse it.

Listing: The ship's off-kilter, maybe a wing is broken or it took a heavy hit. Everyone on board makes skill checks and attack rolls with disadvantage.

Crippled: This ship is in bad shape. Its speed is halved, all attack rolls made by the crew have disadvantage. You're probably not escaping this fight, and capture or destruction is likely.

Wrecked: It's over. The ship is a hulk, beyond repair, just drifting debris.

Ship Movement: Navigating the Void

Ship combat and close-quarters maneuvering are best handled on a battle map, usually with a grid (like 50ft squares, for easy math).

Movement Points (MP): Your ship gets a certain number of "Movement Points" based on its Maneuverability Rating (MR) (e.g., a super agile MR 5 ship might get 5 MP, a clumsy MR 0 ship only 1 MP). Your Pilot spends these points during their Maneuver action.

Cost of Movement & Turns:

Moving Forward: Costs 1 MP for every 50 feet you move (up to your ship's total Speed).

Turning: Turning costs MP based on how sharp the turn is and your ship's MR:

MR 4-5 (Excellent/Good): 1 MP for every 45-degree turn. You're zippy!

MR 2-3 (Average): 1 MP for every 30-degree turn. Still decent.

MR 0-1 (Poor/Clumsy): 1 MP for every 15-degree turn. And you can't turn more than 45 degrees in a single turn. These are your big, slow beasts.

Changing Altitude: You can move up or down too! Costs 1 MP for every 50 feet of vertical change. Yes, we're doing 3D combat!

Flow Travel & Exploration: The Journey is the Adventure!

Long-distance travel between Crystal Spheres, through the Flow, isn't just a montage. It's a dangerous, often epic journey that becomes its own adventure. We're treating this like a Skill Challenge, making the journey itself an active part of the game, with real player choices and consequences.

Planning Your Journey & Navigation (A Skill Challenge!)

Pick Your Destination: First, you gotta know where you're going! Choose your target Crystal Sphere or a major landmark within the Flow.

Designate a Navigator: Someone's gotta be in charge of getting you there. Usually, it's the Pilot, or someone with a good head for Arcana or Navigator's Tools.

Set the Challenge: Your DM will set a Navigation DC (how hard it is to find your way, based on distance, how well-traveled the route is, and how turbulent the Flow is) and a number of Successes Required (like 3 to 5 successes for a typical journey).

Making Progress: Your Navigator (and anyone helping them) makes a series of Intelligence (Arcana or Navigator's Tools) checks over time, maybe once per day of travel.

Success: One success gets added to your total. You're making good time!

Critical Success (Roll 10+ over DC): You're a natural! That counts as 2 successes, meaning you're blazing a trail.

Failure: No progress that day. And your DM might say you burned through extra air or supplies.

Critical Failure (Roll 10+ under DC or Natural 1): Big trouble! This usually triggers an immediate Flow Encounter (see below), or it means you're way off course (adds 1-2 extra days to travel!), or your ship takes some minor stress damage.

Complications: The DM can throw in curveballs that require other skills. Maybe you need a Wisdom (Perception) check to spot a hidden hazard, a Strength (Athletics) check to brace the ship during a cosmic storm, or even a Charisma (Persuasion) check to deal with some unexpected Flow dwellers.

Flow Encounters: What Lurks in the Cosmic Ocean

Encounters in the Flow are less frequent than in Wildspace, but they're usually much more significant. Your DM will roll for these at certain intervals (like once a week of Flow travel, or if you critically fail a Navigation check).

Environmental Hazards: Think turbulent Phlogiston currents that push you off course or stress your hull, astral maelstroms that disorient you and might even rip crew members off deck, or rogue asteroids that need quick Dexterity saves to avoid. These are like environmental puzzles or traps for your ship.

Other Spelljammers: You'll run into other ships out here! Merchant convoys (trade opportunities, or maybe tempting targets?), Giff military patrols (potential inspections or confrontations), aggressive mind flayer dreadnaughts (run!), or desperate pirates looking for easy prey. These often lead straight into ship combat!

Wildspace/Flow Creatures: The cosmos is full of wonders and horrors! You might encounter gigantic astral dreadnoughts (these ancient beasts are unaffected by any metaplot changes, they've always been here!), migratory space whales (beautiful, usually peaceful, but hitting one is bad), or even sentient living astral clouds. These aren't just bags of hit points; they often have unique behaviors and vulnerabilities that make fighting them a real tactical challenge.