Rules Index GM Screen Players Guide

Introduction

Hello and welcome to the Archives of Nethys, the official home of the Starfinder Second Edition system reference documents. Here you can find all the rules, character options, and monsters needed to play Starfinder Second Edition. The Archives houses all of the rules from Player Core as well as every sourcebook that Paizo publishes. By going to the Source tab on the sidebar, you can select a sourcebook and view all the character options that come from that book.

If you're just getting started with Starfinder, you should check out Chapter 1 and Chapter 8 of Player Core for full information on how to play, but we've tried to give a quick summary on character creation and play below.

How to Play

Starfinder is a science fantasy tabletop roleplaying game (RPG) where you and a group of friends gather to play out a story of daring adventurers exploring a galaxy filled with impossible magic, amazing technology, and fantastical alien cultures. More importantly, Starfinder is a game where your character's choices determine how the story unfolds.

Getting Started Starfinder is a d20 game, so most of the dice rolling you will be doing will use a twenty-sided dice (d20), adding your relevant modifier, and comparing it to the Difficulty Class (DC) of the task. If the sum of your d20 roll and modifier is greater than or equal to the DC, you succeeded at the task; if the sum is less than the DC you failed the task. If you beat the DC by 10 or more, or failed by 10 or more, you either critically succeed or critically fail. This method of determining success or failure is used for most tasks in Starfinder, whether that be rolling a skill check to climb or hide, making an attack roll against a dragon, or rolling a saving throw against a poison. Sometimes you will have to roll other dice besides a d20; in all cases the number indicates the number of sides on the die (a four-sided die is a d4, a six-sided die is a d6, etc.) If a number appears before the "d", roll that many dice and add them together (e.g. "4d6" means roll four six-sided dice and add them together). If a rule asks for "d%", you generate a number from 1 to 100 by rolling two 10-sided dice, treating one as the tens place and the other as the ones place.

Your modifier for a task is usually made up of your relevant proficiency bonus and ability bonus, though it may also include various other bonuses and penalties. Other bonuses or penalties come in three types: circumstance, status, and item (you can also have untyped penalties, but not untyped bonuses). If you have more than one bonus of the same type, you use only the highest bonus. Likewise, you use only the worst penalty of each type.

Proficiency is a system that measures a character's aptitude at a specific task or quality. There are five ranks of proficiency: untrained, trained, expert, master, and legendary. If you are untrained, your proficiency bonus is +0. If you are trained, expert, master, or legendary, your proficiency bonus equals your level plus 2, 4, 6, or 8, respectively.

Each creature has six ability scores that represent their raw potential and basic attributes, with higher scores representing more potential. Attribute modifiers for ordinary creatures range from as low as –5 to as high as +5, with +0 representing average human capabilities. High-level characters can have attribute modifiers that range much higher than +5.
  • Strength represents a character's physical might.
  • Dexterity represents agility and the ability to avoid danger.
  • Constitution indicates a character's overall health and well-being.
  • Intelligence represents raw knowledge and problem-solving ability.
  • Wisdom measures a character's insight and the ability to evaluate a situation.
  • Charisma indicates charm, persuasiveness, and force of personality.
Traits Many character options will have traits listed with them, which look like this: Trait. A trait is a keyword that conveys additional information about a rules element, such as a school of magic or rarity. Often, a trait indicates how other rules interact with an ability, creature, item, or another rules element that has that trait. All the traits used in the game are listed on the Traits tab on the sidebar, roughly organized by type.

Some elements of the game have a rarity to denote how often they're encountered in the game world. Rarity primarily applies to equipment and magic items, but spells, feats, and other rules elements also have a rarity. If no rarity appears in the traits of an item, spell, or other game element, it is of common rarity. Uncommon items are available only to those who have special training, grew up in a certain culture, or come from a particular part of the galaxy. Rare items are almost impossible to find and are usually given out only by the GM, while unique ones are literally one-of-a-kind in the game. The GM might alter the way rarity works or change the rarity of individual items to suit the story they want to tell.
Modes of Play In a Starfinder game, three modes of play determine the pacing of each scene in the story. Most of your character's time is spent in exploration, uncovering mysteries, solving problems, and interacting with other characters. The galaxy is filled with danger, however, and characters often find themselves in an encounter, fighting hostile parties when negotiations go south and battling fearsome alien monsters. Finally, time moves quickly when the characters enjoy downtime, a respite from the galaxy's troubles and a chance to rest and train for future activities. Throughout an adventure, gameplay moves between these three modes many times, as needed for the story.

While exploration is handled in a free-form manner, encounters are more structured. The players and GM roll initiative to determine who acts in what order. The encounter occurs over a number of rounds, each of which is equal to about 6 seconds of time in the world of the game. During a round, each participant takes a turn. When it's your turn to act, you can use up to three actions ([one-action]) and one reaction ([reaction]); you can also use free actions ([free-action]) that don't count towards the number of actions you can take on your turn. Most simple things, such as drawing a weapon, moving a short distance, opening a door, or firing a laser pistol, use a single action to perform. There are also activities ([two-actions] / [three-actions]) that use more than a single action to perform; these are often special abilities from your character's class and feats. One common activity in the game is casting a spell, which usually uses two actions. Reactions are a special type of action can be used even when it is not your turn, but only in response to certain events, and only if you have an ability that allows it. Basic actions and activities that can be performed by most characters can be viewed under the Actions/Activities tab on the sidebar.
Reading a Character Option Most character options and actions use a standardized information block, and the common terms are described here.
  • A prerequisite is any minimum ability scores, feats, proficiency ranks, or other prerequisites you must have before you can access this rule element. Feats also have a level prerequisite, which appears above in the header with the feats name.
  • A frequency refers to the limit on how often you can use the ability within a given time.
  • A trigger is the situation that must be met before reactions and some free actions can be used.
  • A requirement is a certain item that must be on hand or a certain circumstance that must be met in order to use an ability.
  • Feats can also have a Special line under their benefit, which describes any special qualities of the rule.
  • A cost is an amount of resource that must be paid to use an ability each time it is used.
  • Spells, and some feats and abilties, have a heightened entry under their benefit, which describes how it changes or becomes more powerful as it's cast at a higher spell rank or as your level increases.
SFS Symbols Throughout the Archives, you will see certain symbols: SFS Standard iconSFS Limited iconSFS Restricted icon. These refer to the availability of that character option for use in Starfinder Society play. Please see the SFS page for more information on what the symbols mean and go to Paizo's Starfinder Society page for information for how to get involved.

Character Creation

For a detailed run through on how to create a character, please see the section on Character Creation from Player Core. The information below is a brief primer and will help you navigate around the Archives to see all the different character options.

Ancestries Your character's ancestry determines which people they call their own, whether it's diverse and ambitious humans, psychic and charismatic lashuntas, energetic and helpful skittermanders, or any of the other folk who call the Pact Worlds home. Ancestries express the culture your character hails from. Within many ancestries are heritages—subgroups that each have their own characteristics. An ancestry provides attribute boosts (and perhaps attribute flaws), Hit Points, ancestry feats, and sometimes additional abilities.

All ancestries can be found under the Ancestries tab on the sidebar. On that page are the 10 ancestries from Player Core, along with other uncommon and rare ancestries from other sourcebooks. On each ancestry's page, you can see some information on that ancestry as well as the mechanical benefits you gain for being of that ancestry. When you select your ancestry, you also gain a heritage and a 1st-level ancestry feat. You can view the available options by clicking on the links at the top of that ancestry's page. You gain further ancestry feats at 5th, 9th, 13th, and 17th level. In addition to the ancestry-specific heritages, all ancestries can instead take a versatile heritage such as borai or prismeni.
Backgrounds Backgrounds describe training or environments your character experienced before becoming an adventurer. All backgrounds are found under the Backgrounds tab on the sidebar. Each background grants two boosts, usually a skill feat, and the trained proficiency rank in two skills, one of which is a Lore skill. Most backgrounds are common and can be selected by any character, but some adventurers come from more distinctive roots and might have uncommon or rare backgrounds. The particular histories behind these rare backgrounds provide specialized benefits.
Classes Your character's class indicates the training they have and will improve upon as an adventurer. Choosing your character's class is perhaps the most important decision you will make for them. All classes can be found under the Classes tab on the sidebar. Each class page has detailed information on how you can play that class, the initial abilities you gain at 1st level, and the class features you gain as you level up. Pay attention to your class's Key Ability Score, as your character gets a bonus to that ability score at first level and it will be the one that sets the DC for your class's abilities and spells.

Along the top of each class's page are a few subpages for that class. You gain class feats according to your class's progression chart which unlock powerful new abilities for your character. You can view all of your class's feats by clicking on the link at the top of the page. Some classes have a focus spells subpage; see the Spells section below for more information and see Focus Spells for complete information. Lastly, all classes have the option to choose a "sub-class" at first level (e.g. the envoy gets to choose a Leadership Style, the mystic gets to choose a Connection, etc.). Pages listing these options will also be listed at the top of the class's page.

Starting at 2nd level, your character can take an archetype's dedication feat instead of one of their class feats. Archetypes allow you to expand the scope of your character's class. Applying an archetype allows you to select archetype feats instead of class feats. Once you have the dedication feat, you can select any feat from that archetype in place of a class feat as long as you meet its prerequisites. All archetypes can be viewed under the Archetypes tab on the sidebar, where they've been divided into several categories that roughly describe their nature. Some archetypes are what're known as class archetypes. These archetypes fundamentally diverge from your class's specialties but still fit within the theme of your class. Class archetypes may be taken at 1st level if they modify some of your classes initial class features. In this case, you gain the 1st level features from your class archetype and must take that archetype's dedication feat as your 2nd-level class feat.
Ability Boosts During character creation, there are 4 steps that are used to determine your attributes. Each attribute modifier starts at +0, representing human average, but as you make character choices, you'll adjust these scores by applying attribute boosts, which increase a score by 1, and attribute flaws, which decrease a score by 1. As you build your character, remember to apply attribute adjustments when making the following decisions. When you gain multiple attribute boosts at the same time, you must apply each one to a different score.
  • Ancestry: Each ancestry provides attribute boosts, and sometimes an attribute flaw. Most ancestries either give 2 specified boosts, a specified flaw, and a free boost or a specified boost and a free boost. Instead of using your ancestry's specific boosts, you always have the option to replace your ancestry's listed attribute boosts and attribute flaws entirely and instead select two free attribute boosts when creating your character.
  • Background: Your character's background provides two attribute boosts.
  • Class: Your character's class provides an attribute boost to the attribute most important to your class, called your key attribute.
  • Determine Scores: After the other steps, you apply four more attribute boosts to attributes of your choice to finalize your starting attribute modifiers.
Skills While your character's ability scores represent their raw talent and potential, skills represent their training and experience at performing certain tasks. Each skill is keyed to one of your character's ability scores and used for an array of related actions. During character creation, you become trained in a number of skills; some of them are specified by your class, background, or selected feats, but you also can freely select several based on your character concept. Having a high Intelligence score gives you additional trained skills. In addition, starting at 3rd level and every odd level thereafter, you can increase your proficiency of any skill, from untrained to trained to expert to master (starting at 7th level) to legendary (starting at 15th level).

Each skill has actions associated with it that use your proficiency in that skill for the check. Some actions are only used by a particular skill, while other general skill actions can be used with different skills for different outcomes. You can see the actions associated with each skill by viewing its respective page under the Skills tab on the sidebar.
Feats Feats represent specialized abilities or training that your character possesses. There are several different types of feats and they are located in different places throughout the Archives. Ancestry feats, archetype feats, and class feats are located on their respective ancestry, archetype, or class page. There are two additional types of feats found under the Feats tab on the sidebar.

Skill feats are indicated by the skill trait and improve upon, or grant additional actions for one of the skills a character is trained in. Some skill feats require that a character be expert, master, or legendary proficiency in a skill before they can be taken. All characters gain skill feats at 2nd level and every even level thereafter, and some classes gain additional skill feats on odd levels.

General feats have the general trait and represent training or abilities that are available to every character regardless of ancestry, class, or skill training, including armor and weapon proficiency and physical toughness. General feats are gained at 3rd, 7th, 11th, 15th, and 19th level. It should be noted that all skill feats have the general trait and can therefore be taken when a character gains the option of a new general feat.
Equipment To make your mark on the world, you'll need to have the right equipment, including armor, weapons, and other magical and mundane gear. All items can be found under the Equipment tab on the sidebar, divided into different categories and subcategories.

At 1st level, your character has 150 credits to spend on armor, weapons, and other basic equipment.
  • Armor, shields, and weapons have all of the mundane armaments needed for combat, as well as ones made of precious materials or that possess special magical abilities.
  • Other nonmagical gear can be found under the adventuring gear category.
  • Consumables are used up when you activate them, and include medical items and grenades
  • Precious Materials can be used to make items with unique properties and other advantages.
  • Upgrades modify armor and weapons when installed into them.
  • Vehicles contains a list of objects that transport you (and possibly your entire party!) on land, sea, or air.
  • Augmentations give you special abilities and bonuses, and are surgically installed into your body.
  • Magic items consist of a vast collection of items you wear on your body, hold, or install into armor or weapons.
Spells Some classes, including the mystic, technomancer, and witchwarper, get access to spellcasting as part of their class features, but other classes can also gain spellcasting ability from their class feats, by taking certain archetypes, or by taking certain ancestry feats that grant focus spells, innate spells, or cantrips. Spellcasting can be either prepared or spontaneous; If you're a prepared spellcaster—such as a technomancer—you must spend time each day preparing spells for that day. At the start of your daily preparations, you select a number of spells of different spell ranks determined by your character level and class. Your spells remain prepared until you cast them or until you prepare spells again. If you're a spontaneous spellcaster—such as a mystic or witchwarper—you choose which spell you're using a spell slot for at the moment you decide to cast it. This provides you with more freedom in your spellcasting, but you have fewer spells in your spell repertoire, as determined by your character level and class. When you make your daily preparations, all your spell slots are refreshed, but you don't get to change the spells in your repertoire.

All spells can be found under the Spells/Rituals tab on the sidebar. There are four traditions of spellcasting (arcane, divine, occult, and primal) and each tradition has access to a different list of spells that they can cast.

Characters of spellcasting classes can cast a certain number of spells each day; the spells you can cast in a day are referred to as spell slots. At 1st level, a character has only a small number of 1st-rank spell slots per day, but as you advance in level, you gain more spell slots and new slots for higher-rank spells. A spell's rank indicates its overall power, from 1 to 10. Additionally, both prepared and spontaneous spellcasters can cast a spell at a higher spell rank than that listed for the spell. This is called heightening the spell. A prepared spellcaster can heighten a spell by preparing it in a higher-rank slot than its normal spell rank, while a spontaneous spellcaster can heighten a spell by casting it using a higher-rank spell slot, so long as they know the spell at that rank. When you heighten your spell, the spell's rank increases to match the higher rank of the spell slot you've prepared it in or used to cast it. This is useful for any spell, because some effects, such as counteracting, depend on the spell's rank, but many spells have additional specific benefits when they are heightened, such as increased damage. These extra benefits are described at the end of the spell's stat block.

Special Types of Spells

A cantrip is a special type of spell that's weaker than other spells but can be used with greater freedom and flexibility. Casting a cantrip doesn't use up your spell slots; you can cast a cantrip at will, any number of times per day. A cantrip is always automatically heightened to half your level, rounded up. For a typical spellcaster, this means its rank is equal to the highest rank of spell slot you have.

Focus spells are a special type of spell attained directly from a branch of study, from a deity, or from another specific source. You can learn focus spells only through special class features or feats, rather than choosing them from a spell list. Furthermore, you cast focus spells using a special pool of Focus Points—you can't prepare a focus spell in a spell slot or use your spell slots to cast focus spells; similarly, you can't spend your Focus Points to cast spells that aren't focus spells. It costs 1 Focus Point to cast a focus spell. When you gain your first focus spell, you also gain a focus pool of 1 Focus Point. You refill your focus pool during your daily preparations, and you regain 1 Focus Point by spending 10 minutes using the Refocus activity. Focus spells are automatically heightened to half your level rounded up. Taking feats can give you more focus spells and increase the size of your focus pool, though your focus pool can never hold more than 3 points. The focus spells available to a class are listed under that class's focus spell subpage, and all focus spells can be viewed under Focus Spells subpage of the Spells/Rituals tab on the sidebar.

Certain spells are natural to your character, typically coming from your ancestry or a magic item rather than your class. If you have an innate spell, you can cast it, even if you aren't a spellcaster or it's not of a spell rank you can normally cast. You can't use your spell slots to cast your innate spells, but you might have an innate spell and also be able to prepare or cast the same spell through your class. You also can't heighten innate spells, but some abilities that grant innate spells might give you the spell at a higher rank than its base rank or change the rank at which you cast the spell.

Rituals

A ritual is an esoteric and complex spell that anyone can cast. It takes much longer to cast a ritual than a normal spell, but rituals can have more powerful effects. Rituals can have multiple characters working together to cast them and use a variety of skill checks to determine their effect.
Setting The Setting tab on the sidebar has information specific to the Pact Worlds campaign setting, though it can be adapted to any home game. The Deities and Domains subpages detail information about the various divinities of the Pact Worlds and the abilities they offer. Any character can worship a deity, but some classes require it. The Languages subpage has information on the different languages. Characters start with certain languages from their ancestry as well as additional languages from their Intelligence modifier, though they can gain even more by taking the Multilingual skill feat. The Planes subpage has information on the different planes of existence; most campaigns take place in the Universe but characters can find themselves is far-flung locations such as Heaven, Hell, or the Outer Rifts. The Articles subpage summarizes the articles that can be found in each Adventure Path.

Gamemastering

In a game of Starfinder, the Game Master (often abbreviated GM) is the player in charge of the story and the world the other players are exploring with their characters. It is recommended that any new GM fully understands Chapter 1 and Chapter 8 of Player Core, and Chapter 1 of GM Core.

Creatures The Creatures tab on the sidebar has the stat blocks for all of the monsters and NPCs that are published in bestiaries (they do not include custom monsters or NPCs that were created for Adventures or Adventure Paths). From the subpages you can view all of the monsters or NPCs, or you can select a letter to view the creatures whose name or family name start with that letter. Information on how to read a creature's stat block can be found in Reading Creature Statistics. On the Archives, if the creature is part of a larger family of related creatures, then the information for that family and other related creatures will be listed at the bottom of the stat block. Standard abilities for creatures can be found under the Abilities subpage.

The Hazards tab on the sidebar contains the various published traps and environmental hazards, organized by complexity and level.
Rules All of the rules from the various source books can be found under the Rules tab on the sidebar. This includes the complete set of rules from the Player Core, help for GMs from the GM Core, and every new rule introduced from sourcebooks. The rules are organized by sourcebook and related rules from different sourcebooks are cross-linked to one another. Also on the Rules page is the GM Screen, which is a quick reference to helpful rules and tables for use during play.

While adventuring, characters (and sometimes their belongings) are affected by abilities and effects that apply conditions. Conditions can be found under the Conditions tab on the sidebar. Conditions change your state of being in some way, and they represent everything from the attitude other creatures have toward you to what happens when a creature drains your blood or life essence. Diseases and poisons are types of afflictions, as are curses and radiation. An affliction can infect a creature for a long time, progressing through different and often increasingly debilitating stages. Most diseases and curses can be found under the Afflictions tab on the sidebar; curses, diseases, and poisons inflicted by a creature or a spell can be found on their source's page.
Quick Links Here are some quick links to common rules

Aerial Combat
Afflictions (Curses, Diseases, Poisons, Radiation)
Aquatic Combat
Basic Save
Cover
Counteracting
Critical Specialization Effects
Damage Types
Darkvision
DCs by Level
Disrupting Actions
Drowning and Suffocation
Effect Areas
Environmental Damage
Falling Damage
Flat Check
Focus Spells
Forced Movement
Hit Points, Healing, and Dying
Hostile Actions
Light
Low-light Vision
Mounted Combat
Multiple Attack Penalty
Scent
Senses
Shield Rules
Starvation and Thirst