Spelljamming Ships and Helms

Ships travel through wildspace by means of the helm: a magical device which converts mystical energy into motive force, the push that moves the spelljammer. This allows rapid movement from planet to planet. Some of the specifics vary from race to race. In general, however, most ships are equipped with a magical device known as a spelljamming helm.
The spelljamming helm is a chair of elaborate design and intricacy, with recesses for the head, feet, and arms of the person using it. The styles of helms vary from simplistic and functional to ornate and gothic.
A mage or priest sits at the helm and acts as a living engine, providing the magical power to move the ship through wildspace and to perform some basic maneuvering as well. A character with either of the appropriate arcane backgrounds for a Major or Minor Helm (the most common types) can attune to the helm by concentrating for a few minutes (this might require application of the dramatic task rules in an emergency).
Once attuned, the user’s becomes sensitive to the state of the ship (but not that of any passengers) and can see events outside as if they were standing on any point outside it (and can change this viewpoint at will). The user cannot use their arcane background while attuned to the helm, but can break the attunement at any time by merely standing up (a free action).
A helm generates motive forces, but does so in a way that requires guidance and assistance, which is provided by the sails, rigging, rudder, etc.--all the mundane elements of a ship. When the helm is installed and active, its magic enchants these mundane elements to aid in controlling and directing the motive force generated by the helm. The helmsman may make boating skill rolls to pilot the ship, and the crew can cooperate in these rolls. If the helmsman breaks the attunement, the ship loses all power until a helmsman attunes to the helm again. The ship will drift at tactical speed in a straight line until someone else takes the helm or the ship hits something.
Spelljamming typically consumes 1 Power Point (PP) per hour of cruising. Power points are not recovered while the user is ’helming’ a ship.
Helms are incredibly durable and nearly indestructible, artifacts of great power. As such, they are INCREDIBLY expensive.

Jamming Speed

A spelljammer powered by a helm can move incredibly quickly (100 million miles per day) when not hampered by the presence of a significantly large body, or gravity well. This higher speed is called "jamming speed".
Jamming speed covers tremendous distances very quickly. It is the default speed of space travel and vessels only slow down when there is an object of significant size (10 tons or greater) nearby. Usually this is a planet of some kind, but it can also be the presence of another ship of some sort.
This "sudden stop" when moving at high speeds does not affect anyone riding on the ships. The effortless deceleration is believed to be created primarily as a safety factor to prevent spelljamming ships from colliding with other ships, meteors, asteroids , and planetary bodies. In reality, this often means that a ship enroute from one point to another in a (relatively) more crowded section of space may have more encounters than a ship moving through an emptier area (out beyond the farthest planet, for example) so the ship has to continually slow down between locations.
Once out of the influence of the object or planet, the helmsman can prepare the helm to jump to spelljamming speed again, which typically takes a few minutes. Larger, more massive celestial bodies have larger gravity wells, and require the spelljammer to be farther away to attain jamming speed.

Tactical Speed

The slower speed when under the influence of an object or planet is called "Tactical Movement" and is controlled by the Ships Rating, or SR. While jamming speed is a constant amongst all spelljamming vessels, the SR is a direct measure of the power of the pilot. The more powerful the pilot and helm, the higher the SR will be. E.g. for a Major Helm the SR is the Helmsman’s Spellcasting Skill/2; for a Minor Helm, the SR is the Helmsman’s Spellcasting Skill/3.

Wildspace Navigation

Within most systems navigation is not difficult, just a more complicated version of terrestrial navigation by the stars utilizing three-dimensional instruments. Navigation uses the Astrogation Skill. To calculate navigation and travel times:

• Estimate the base minimum travel time between two points, and add 25% for a default "good" transit. (E.g., if the base is 20 days, then the default travel time is 25.
• Have the navigator make an Astrogation role. This can be Supported by up to two others, as long as they also have Astrogation. 
• Add +1 to the roll if the navigator has access to star charts for the system, or +2 if the ship is equipped with a planetary locator. (These do not stack). 
• This roll assume that the navigator has access to the necessary instruments. If not, -4 to the roll.
• There may be special modifiers to this roll based on circumstances, as judged by the DM. E.g., large gas clouds or other debris might obscure vision, make this navigation more difficult. 
• On a success, the transit time is the default. On a raise, it is the minimum. On a failure, add 25% to the travel time. On a critical failure, the ship ends up in the wrong place after the default travel time. 

Detail Articles

• Types and Cost of Helms
• Ships and Weapons Stats
• Outfitting Ships
• Crew Upkeep and Carousing
• Sell Goods, Cargo and Ships
• Ship Combat and Repairs