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Exploring the Galaxy

Exploration System

Source Galaxy Exploration Manual pg. 34
Perhaps one of the biggest challenges of having an entire galaxy to explore is figuring out where to start! With limitless stars ahead, each with the potential for multiple worlds to investigate, the task of picking a destination can be daunting to say the least. The exploration system presented in this section gives your party of galactic adventurers a wide range of tools to seek out new worlds.
Over the course of many adventures, your character may travel to a far-flung locale in the Vast, catalog a specific planet within a star system, attempt to locate something from orbit, or explore a previously unknown world on foot. No matter the scope of exploration, Starfinder provides a system for it in the following sections, starting with wide-ranging galaxy exploration and narrowing in focus to world exploration.
Galaxy Exploration (see below) expands upon the standard rules for the navigation task of the Piloting skill, especially when you know next to nothing about the system to which you wish to travel. By doing research and gathering more information, you can learn enough about the system to make it merely unfamiliar. Once you locate a system and travel to it, the next logical step is to explore the system itself. The System Exploration section (page 35) gives you tools to track down the various gravity wells within a system and, with a little time and effort, create a map of the system.
Once you’ve reached a particular world, Exploration from Orbit (page 36) provides guidelines for getting the most from your starship’s sensor readings while in orbit. It covers not only general information on what your sensors can ascertain, but also how to focus on and analyze data to gather information about a world’s attributes, anomalies, and inhabitants.
The last section, World Exploration (page 37), gives some general guidance on how to handle on-the-ground exploration on a new planet, including using the tools presented in the biome sections of this book (pages 48–95). It also provides a system called hexploration to help you narrate and map the exploration of a world.
Downtime Activities: Several components of this system use Starfinder’s downtime rules.

Galaxy Exploration

Source Galaxy Exploration Manual pg. 34
Long ago, galactic exploration was primarily the business of a diverse and often secretive group of priests and other magic‑using fellowships who jealously guarded their secrets of magical space travel and planes-hopping. With the revelation of Triune and the advent of faster-than-light Drift travel, the galaxy became ripe for mass exploration, but only for those with the technology and know-how to navigate its expanse.
Navigation is the key to exploring the galaxy. Every navigator is aware of the difference between Near Space and the Vast. Near Space comprises systems and worlds that have the greatest density of Drift beacons, thereby reducing the time and risk it takes to travel there. Destinations in the Vast have fewer such beacons, increasing both the travel time and risk of potentially dangerous Drift encounters (pages 146–147), and making reliable information on such places even harder to come by.
While a navigator must be knowledgeable in various calculations and equations to feed into Drift engines, they also must have at least some knowledge of where they want to go. While strange properties of the Drift make the galactic distance from one place to another almost meaningless, knowing a system’s relative bearing from one’s current position (and that said system even exists) is needed to properly navigate via the Drift. These details can be hard to ascertain, especially when searching for a path to a world in the Vast.
If you want to find and travel to a known destination, even one unfamiliar to you (Core Rulebook 145), you can. You might even use the plan route downtime activity (Character Operations Manual 154) to gain some aid toward navigating to that system. But what about destinations, especially those in the Vast, about which little is known? Maybe you’ve found some brief reference to a system on a datapad, heard rumors about a mysterious space station, or uncovered some old but faulty star chart. For such obscure destinations, you can attempt to narrow your search by using the Locate Galactic Destination downtime activity.

System Exploration

Source Galaxy Exploration Manual pg. 35
Once you’ve located and successfully traveled to an unfamiliar system, your next step is learning what exactly is in that system—no easy task, considering it may be hundreds of millions of miles across. Entering the system might give you some fundamental information about what’s present there, and you might have learned some particulars already through your initial search. To learn more about an unknown system, many explorers rely on the activities and starship systems detailed below. See pages 394–395 of the Core Rulebook for brief summaries about various types of astronomical objects you might encounter.

Finding Gravity Wells

Source Galaxy Exploration Manual pg. 35
Gravity wells are formed when massive astronomical objects exert significant gravitational pull, such as a star or black hole around which a system’s other astronomical bodies orbit. When you arrive in a system, you can typically discover its primary gravity well very quickly and without the need for skill checks.
You can then attempt to locate other astronomical objects in a system by searching for their telltale gravity wells. The most basic (and time-consuming) method for doing so involves searching the system via a starship’s sensors, using the map star system downtime activity. You can then determine the nature of the astronomical objects you locate (see Analyzing System Data below).
Due to the massive sizes of star systems and the relatively small size of even the largest planets and other bodies, finding all of a system’s gravity wells and corresponding worlds takes time. Traveling via starship to an identified astronomical object works as traveling in-system, taking 1d6+2 days.

Starship Systems

Source Galaxy Exploration Manual pg. 35
There are widely available starship systems that can speed up the time it takes to map a star system. This tech include very long‑range system-wide sensors that, while not useful in combat, can quickly scan a star system and produce a general map as well as sensor drones that you can deploy throughout a system. Such drones are slower but more affordable than system-wide sensors.

Analyzing System Data

Source Galaxy Exploration Manual pg. 35
After pinpointing a system’s gravity wells, you may want to determine exactly what kind of astronomical object lies at the heart of each well, especially before investing the time it takes to travel to one. This requires further analysis of the data.
To analyze gravity well data and identify the type of astronomical object at its heart, you must first have pinpointed the gravity well, whether by successfully completing the map star system downtime activity, analyzing sensor drone data, or coming into possession of the necessary information some other way. Then you can perform the Celestial Analysis downtime activity.

Exploration From Orbit

Source Galaxy Exploration Manual pg. 36
While you can ascertain the location and general type of astronomical objects from a distance, finding out more generally requires traveling to and orbiting the body. While in orbit, you can use your starship’s sensors to determine the world’s atmosphere, primary biomes, and gravity. This process typically takes ten minutes and requires a successful DC 15 Computers check, as detailed on page 301 of the Core Rulebook. This check is modified by the type of sensors you have on your ship, as usual. A number of factors can increase or decrease that DC, as outlined in the Sensor Modifiers below.
Keep in mind that such scans must be performed outside of combat and that certain worlds’ inhabitants will not permit offworlders to peer down from orbit indefinitely—or at all.
While getting general information about a world can be crucial, more information can be gained from a full sensor sweep and analysis of the data obtained. You can use the world analysis downtime activity to attempt a more thorough scan, or you can map out a portion of a world’s geography using the world mapping downtime activity.

Sensor Modifiers

Source Galaxy Exploration Manual pg. 37
Various circumstances might modify the DC for the checks needed to ascertain information about a planet while using sensors in orbit. The following is a list of some of those circumstances and how they modify the DC. Modifiers from two or more different sources can stack (such as if a planet has both a thick atmosphere and an extreme magnetic field). Strange anomalies may hamper scanning at the GM’s discretion; see the Planetary Anomalies below.

CircumstanceDC Modifier
Anomaly–2 to +4
Energetic magnetic field+2
Extreme magnetic field+4
Planetary sensor scrambler+4
Thick atmosphere+2
Thin atmosphere–2

Planetary Anomalies

Source Galaxy Exploration Manual pg. 37
Anything that makes a world unique beyond its basic physical and cultural characteristics can be considered a planetary anomaly. This could manifest as a strong connection to a different plane of existence, a global magic- or technology-dampening field, an abundance of mystical crystalline caverns just below the surface, especially active plate tectonics, or a singularity barely contained within the planet’s core.
Each biome section (pages 48–95) and most cultural attributes (96–129) contain tables of adventure hooks, which can be a great source of inspiration for planetary (or more localized) anomalies. Feel free to adapt ideas from your favorite books, films, and other media, and remember that the only limit in a science fantasy setting is your imagination.

World Exploration

Source Galaxy Exploration Manual pg. 37
Exploration-focused adventures and campaigns often take place on a single uninhabited or previously uncontacted world, or in a system of such worlds. Exploring a world whose inhabitants are willing to interact with outsiders and who have some degree of technological advancement can be as easy as getting the proper permissions to land your starship, buying a map, and booking a guided tour. In such places, you’ll often be able to use a large settlement as a base of operations. There, you might hire guides, purchase or rent terrestrial transportation, and stock up on the necessities of exploration before setting out, as you would in any major settlement of the Pact Worlds.
Even without these benefits, you are likely to have enough information from whatever led you to the world in the first place, or from your exploration from orbit, to have a general location from which to begin your exploration. A relatively small terrestrial world still contains uncountable lifetimes’ worth of adventure in its millions of square miles. You’re likely to focus on key areas of interest in your exploration, rather than make a comprehensive mapping of a world’s every rock and tree.
But what happens when you lack a known starting point, or the world doesn’t have large cities or advanced technology—or even any sapient creatures? Well, things may get trickier for both the player characters and the GM. The Sandbox Adventures chapter (starting on page 130) contains advice for creating and facilitating open-ended campaigns and adventures, while this section provides a “hexploration” system that GMs and player characters can use together to explore and map uncharted areas. Hexploration is detailed in the following sections, which assume the PCs have landed their starship in a relatively safe location and are traveling on foot in trackless terrain on an uncharted terrestrial world.
Finally, the various biome sections in this book (pages 48–95) detail not only the kinds of environments, both familiar and alien, that you might encounter, but also potential inhabitants and adventure hooks. Each section also presents player options, such as equipment, feats, and spells, that can be especially useful in exploring such areas. It’s then up to the players to collaborate, using these and other tools along with the explorers’ decisions to weave together a fun and exciting story of the exploration of an alien world.

Hexploration Map

Source Galaxy Exploration Manual pg. 38
Hexploration uses a map split into a hexagonal grid. Each hex on the map represents an area 12 miles across and features its own dominant biome, be it desert or forest, marsh, or mountain— see the Hexploration Table on page 39 for a full list of biomes. Terrestrial worlds with dynamic climates often have most, if not all, of these terrain types, while stranger worlds might feature only one or two dominant biomes across their entire surface. Just because each hex has a primary terrain type doesn’t mean that it’s the only terrain in that hex. A hex might feature a road or river snaking through it, smaller bodies of water, a thicket of alien vegetation, a massive city, or countless other variations.
You can quickly draw a map using just a few colors, some basic symbols, and letters or numbers for reference; the Exploration Log on page 158 includes a hex grid for this purpose. When creating a hex map—often when the PCs land their starship or set out from a settlement—it’s helpful to start in the middle of the grid, since they can generally explore in any direction.

Hexploration Activities

Source Galaxy Exploration Manual pg. 38
A group of PCs gains a number of hexploration activities per day based on the speed of the slowest member of the group, as shown on the table below. During the course of the day, the PCs can use their hexploration activities to either travel or perform recon.

SpeedActivities per Day
15 feet or less1/2
20–25 feet1
30–35 feet2
40-45 feet3
50 feet or more4


Source Galaxy Exploration Manual pg. 38
You move into or toward an adjacent hex. This requires a number of hexploration activities equal to the required activities (see the Hexploration Table on page 39) for both your origin hex and the hex into which you’re moving. For example, a party moving from a mountain into a forest would require 5 hexploration activities. If you don’t know the biome of the destination hex, you learn it after using the number of exploration activities required by your origin hex (2 in the previous example). If you don’t have enough hexploration activities in a day to move into an adjacent hex, you can use as many hexploration activities as you want to move toward that hex, and then add that progress to travel you perform on subsequent days.
Keep in mind that with hexploration, movement from one hex to another includes some degree of exploration of the hex entered rather than point-to-point travel, so the travel rate is often slower than typical overland speed.
Traveling in Vehicles: Remember that a vehicle must be designed for the terrain in which it’s traveling to use its overland movement speed; the GM makes this determination per vehicle and can modify the speed as needed. If the entire party is in appropriate vehicles with an overland speed of at least 20 mph, the group gets 6 activities per day instead of the usual 1–5.
Traveling in a Starship: While it is often possible to fly a starship slowly enough and at a low enough altitude to easily travel over difficult terrain while gathering basic information, there are myriad reasons why this may not be advisable or preferable. Foremost, many of a world’s most interesting features are hidden from view and are fundamentally inaccessible from the air. There may be other concerns, such as an atmospheric field that interferes with technology or a strict local government with large no-fly zones. In addition, Huge or larger starships flying too close to a planet’s surface risk crashing.

Perform Recon

Source Galaxy Exploration Manual pg. 39
You carefully explore and map a single hex, gaining as much information as you can. This requires a number of hexploration activities equal to the hex in which you’re performing recon, and you choose whether to be more careful or more thorough. If you choose to be more careful, the encounter DC (see Random Encounters below) increases by 2; if you choose to be more thorough, it decreases by 2.
Once you have successfully performed recon in a hex, you discover all the hex’s major features that do not require a check (at the GM’s discretion), and you learn the biome of each hex adjacent to that hex. In addition, if you chose to be more thorough, you also find the fastest way through the terrain; reduce the number of activities required to travel in or through that hex by 1 (to a minimum of 1). This reduction can apply only once per hex.

Downtime Activities

Source Galaxy Exploration Manual pg. 39
Characters not traveling or performing recon can spend the day engaged in a downtime activity instead. Several existing downtime activities can be especially relevant during exploration of unfamiliar terrain. More information about each of the following can be found in the Character Operations Manual: build shelter (page 150) gather supplies (page 152), inoculate (page 153), maintain readiness (page 153), and secure area (page 155).


Source Galaxy Exploration Manual pg. 39
When exploring a world’s unmapped wilderness, the Survival skill (Core Rulebook 148–149) becomes crucial to, well, survival. From enduring severe weather and orienteering to predicting weather and living off the land, the tasks of this skill are particularly suited to the galaxy’s wilds. Precisely what you will face is dependent on the biome you are exploring, and there may be numerous environmental hazards (Core Rulebook 400– 405).

Random Encounters

Source Galaxy Exploration Manual pg. 39
Whenever PCs explore, there’s a chance for a random encounter; this chance is based on the relative population density of an area, with some types of terrain tending to be denser than others. Each time the PCs travel or recon, roll a d20. On a roll equal to or higher than the encounter DC listed in the Hexploration Table (see below), a random encounter occurs. The GM can adjust these numbers based on circumstance.
The GM can use the inhabitants and adventure hooks tables in the corresponding biome section (pages 48–95) to inspire a random encounter. Remember that encounters can be far more than combat with wandering monsters; there are plenty of opportunities for roleplaying and social encounters, especially those that tie into and expand on a world’s adventure hooks or various other attributes.


BiomeRequired ActivitiesEncounter DC
* Assumes a fly (airborne or space) or swim (aquatic) speed; GM might require certain equipment and/or might increase the required activities.

Switching out of Hexploration

Source Galaxy Exploration Manual pg. 39
When the PCs face a random encounter or discover an adventuring site while engaged in hexploration, these encounters typically do not cost the PCs a hexploration activity to tackle, assuming that they occur over several minutes rather than hours. However, if the PCs decide to explore a vast technological ruin, engage in lengthy diplomacy with locals, or get involved in a protracted chase with raiders, the GM might deduct a hexploration activity for the time spent.