Loader image
Loader image
Back to Top


Nerdarchy > Dungeons & Dragons  > Spelljammer ship combat primer for 5E D&D
RPG pillars

Spelljammer ship combat primer for 5E D&D

Absolute Tabletop takes the Oath of the Frozen King with Nerdarchy
Satine Phoenix is living the nerdy dream

You can’t throw a d20 in 2017 without hitting a space fantasy RPG. Tabletop gamers looking to combine swords and sorcery with science and starships can take their pick of several products hitting the market this year. Starfinder utilizes the Pathfinder engine to explore fantasy space, while Harbinger and Hyperlanes build on 5th edition Dungeons & Dragons to offer rules and guidelines for extraterrestrial questing, for a few examples.

Spelljammer boxed set cover art by Jeff Easley

Cover art from the original 2nd edition AD&D Spelljammer boxed set. Art by Jeff Easley

Before any of these exciting products hit the market, my home game blasted off in an unexpected direction early in the campaign thanks to A Fistful of Dice-inspired Nerdarchy video about running a 5th edition Dungeons & Dragons game using the Spelljammer setting from 2nd edition AD&D. Spelljammer was a quirky, off-the-wall boxed set created during a period when TSR offered lots of different campaign settings like Dark Sun, Al-Qadim, Greyhawk, Forgotten Realms and the world of Dragonlance.

Presented as a way to link all of the various settings, Spelljammer offered an entire cosmology of solar system-encasing crystal spheres floating in a phlogiston that allowed astonishingly fast travel between them aboard spelljamming ships. Replacing science and technology with magic, spelljammers operate by a spellcaster powering a magical chair that moves the ship and creates an atmosphere around each vessel.

The mechanical aspects of the original Spelljammer material are fairly easy to adapt to 5E rules. Nate the Nerdarch wrote an article adapting some of the rules into 5E terms, while WebDM created a video about their own launch of a Spelljammer campaign where they discuss how a lot of material translates almost whole cloth into 5E D&D. For instance the random tables for system and planet creation can be used right out of the original sourcebooks.

For my taste, I approached the concept with a minimal amount of rules and guidelines, opting instead to inject the flavor of the setting over the crunch. At the conclusion of my players’ first arc, they discovered a strange sunken ship and, sitting on the helm, quickly found themselves carried far above the surface of their planet.

It’s been a long, strange trip ever since.

Running the campaign continues to be a huge amount of fun for me and the players. The party has made business deals with a lounge-singing beholder, risked madness in the lair of fungal insectoids turning dwarves into genetic goop and fended off sentient asteroids. Along the way, they’re gathering a crew that so far includes a goliath impound lot attendant, a bone-headed scro warrior, an animated skull made of pizza, a critically-successful cartographer/impromptu sketch artist and more.

Ship-to-ship combat in Spelljammer between a galleon and an illithid nautiloid. Art by Jonathan Ascher

But one area that we have yet to explore is spelljammer ship combat. They’ve had a few encounters in wildspace on their way to and from various crystal spheres in the pursuit of fulfilling contacts, but I feel remiss in not providing more opportunities to take advantage of the uniqueness of their situation. Fortunately, they’ve only just become 6th level characters with a lot of story left to go so there’s ample time to test the limits of their ship Illrigger and the ace pilot they recently hired.

To that end, I rewatched those videos, reread the source material and researched some homebrew stuff online to come up with a way to handle spelljammer ship combat that fits my needs. One of the best repositories of Spelljammer content on the internet is Lost Spheres, which while no longer maintained and containing info only through 3rd edition D&D, nonetheless holds a galaxy of interesting lore, mechanics and ideas for running a Spelljammer game.

Sifting through the site uncovered a ship combat system for 3rd edition D&D that’s fairly clean and concise. The document is 18 pages long and full of great ideas for running ship-to-ship combat between spelljamming vessels. I’m still processing a lot of the information but it seems reasonable that much of it could be useful for more traditional naval combat in your D&D game, too.

For gamers who might be interested in adding some Spelljammer flavor into your 5th edition D&D game, here’s a few 5th edition D&D additions and adaptations inspired by the ship combat rules from Lost Spheres and my take on how spelljamming works in 5E.

The spelljammer helm

The core of a spelljamming vessel, these magical artifacts allow those will spell slots to attune to the ship they’re installed in and become magically linked to the vessel. The pilot gains an awareness of the ship and, under normal operation, can move and maneuver the ship for up to eight hours. Pushing beyond this time limit gives the pilot a level of exhaustion for every additional eight hours at the helm without a long rest.

This comes into play for crews to make sure they have multiple people capable of piloting the ship. Even though travel through wildspace and the phlogiston takes place at ridiculously high speeds, it can still take weeks or months to travel from a planet in one crystal sphere to another. Also, if your crew only has a single spellcaster and they get incapacitated or killed, the ship will be stranded.

Normal operation also creates a temporary atmosphere and gravity field around a ship, which contains a pocket of air that degrades over time.

Spelljammer combat primer

Spelljammer ships come in lots of strange shapes and sizes.

When your spelljammer finds itself in combat, initiative rolls are made for each ship, or each entity propelling itself through space in the case of things like cosmic dragons and the like. Because the pilot at the helm is in control of the ship, they will modify the initiative roll. However, instead of adding their Dexterity modifier to the roll, add their level (for independent creatures add their challenge rating). This represents the pilot’s ability to harness their magic or a creature’s experience in space.

When initiative is rolled, or at the start of the ship’s turn on any round, the pilot can expend one spell slot of any level to give the ship +5 initiative. There is no limit to the number of spell slots that can be spent on increasing initiative in this way.

During the ship’s turn, those aboard take their actions, which includes using the ship’s weaponry. Since a ship’s crew all take their actions on the same turn, individual characters don’t need to roll for initiative. Instead, it’s an opportunity for players aboard a ship to discuss and agree on tactics and actions they’ll take each turn, in whatever order they wish.

All ships and space-traveling creatures begin combat at a speed of 1. On a ship’s turn, the pilot can expend one spell slot of any level to increase the ship’s speed by 1. There is no limit to the number of spell slots that can be spent on increasing ship speed in this way. If a new round starts and a ship’s speed exceeds any other’s by 5 or more, they may successfully escape.

All about them spell slots

Spell slots are the bread and butter of a spelljammer pilot. Since helming a ship means a character is tethered to the ship in this manner, there’s several ways the pilot can still be involved in the action. In fact, their manipulation of spell slots are perhaps the most vital actions that take place during spelljammer ship combat.

  • A helmsman running low on spell slots can use a bonus action to take a level of exhaustion and create two first-level spell slots on the ship’s turn.
  • A helmsman can expend one spell slot of any level as a bonus action to gain advantage on a maneuver roll made during that turn
  • Maneuvers are special actions that the helmsman can take each turn on the ship’s initiative. The helmsman adds their spellcasting ability modifier to the roll. If they have proficiency with vehicles (spelljammers) they can add their proficiency bonus as well.
    • Normal operation: DC 10 – maintain the ship’s present speed and position in combat.
    • Offensive maneuver: DC 20 – all attack rolls from the ship have advantage until the start of the ship’s next turn.
    • Defensive maneuver: DC 20 – all attacks made against the ship until the start of the ship’s next turn are made with disadvantage.
    • Full offense: DC 25 – all attacks from the ship are made as if the targets had vulnerability to all damage. All attack rolls made against the ship until the start of the ship’s next turn are made with advantage.
    • Full defense: DC 25 – all attack rolls made against the ship until the start of the ship’s next turn are made as if the targets had resistance to damage. All attacks from the ship until the start of the ship’s next turn are made with disadvantage.
    • Ram: DC 20 – the attacking ship deals damage equal to its tonnage multiplied by the ship’s current speed. The attacking ship takes damage equal to the tonnage of the ship that is rammed. In the case of creatures this damage equals 3d10, plus an additional 1d10 for each size category above medium. Creatures within 15 feet of the point of impact must make a Dexterity saving throw (DC 20) or take 4d6 bludgeoning damage and be knocked prone. A successful save results in half damage, and the creature is not knocked prone. If the ramming ship is equipped with a ram or otherwise specially reinforced for such maneuvers, the damage dealt to the ramming ship is halved, and creatures aboard that ship have advantage on the Dexterity saving throw.
    • Failing a maneuver roll puts the ship in a vulnerable position. Attack rolls from the ship have disadvantage, and attack rolls made against the ship have advantage until the start of the ship’s next turn.

A neogi death spider squares off against a nautiloid in wildspace in the Spelljammer campaign setting.

It should work … in theory

Game play at my group’s table tends to be fairly fast and loose. I’m grateful to DM for players who are incredibly laid-back and willing to experiment with unusual rules and situations for their characters. We follow the One Rule of gaming, so even if something doesn’t turn out to work so well we roll with it, adapt or change things and move forward.

The spelljammer maneuvers above and the other material in the ship combat document have yet to be playtested with my group. In our campaign so far, we’ve had one ship-vs.-creature combat and a few smaller random encounters that took place on the deck during travel. Since we’re flying our spelljammers by the seat of our pants we tend to make a lot of stuff up on the fly as we barrel along. In our next session I plan to present an opportunity for ship-to-ship combat so we can implement these maneuvers into our game and see how that goes.

Spelljammer logo by Doug Watson

The Spelljammer logo. Design by Doug Watson

If you’ve played any Spelljammer D&D games or if you’re interested in learning more about the setting and some of the ways I’ve adapted it for 5th edition D&D, please leave a comment below and let me know.

And with that, until next time, stay nerdy!

Want to watch Nerdarchist Dave run a Spelljammer game for Nerdarchy? The annual Thanksgiving Eve Spelljammer game started here!

[youtube https://www.youtube.com/watch?v=O3GtD2Gz79A&w=560&h=315]

[amazon_link asins=’0880387629,1560760834,B002ZFK2IS’ template=’ProductCarousel’ store=’nerdarchy-20′ marketplace=’US’ link_id=’bd5daf4c-3fea-11e7-8c81-4576ea38f7db’]

Digiprove sealCopyright protected by Digiprove © 2017 Nerdarchy LLC
Doug Vehovec

Nerditor-in-Chief Doug Vehovec is a proud native of Cleveland, Ohio, with D&D in his blood since the early 80s. Fast forward to today and he’s still rolling those polyhedral dice. When he’s not DMing, worldbuilding or working on endeavors for Nerdarchy he enjoys cryptozoology trips and eating awesome food.


  • Cory Smith
    June 10, 2017 at 1:54 pm

    Hey, I’ve got a group that is interested in using Spelljammer for our setting. 3 of the players would like to rotate in/out as DMs, and we think this setting would lend itself to that. Whoever is DMing takes the role of the captain and and whoever is playing will be on the away team for the length of that particular story arc. I’d appreciate any thoughts or advice you have.

Leave a Reply

Nedarchy the NewsletterJoin and Get $9.99 in Free Digital Products from Nerdarchy the Store!
%d bloggers like this: