Starfinder 2E - Chapter 8: Playing the Game

Source URL: https://2e.aonsrd.com/rules/311-chapter-8-playing-the-game

Three Modes of Play

Check System (Foundation)

Four-Step Check Process

1. Roll d20 and identify modifiers, bonuses, penalties
2. Calculate total result
3. Compare to DC
4. Determine degree of success

Check Formula

d20 + attribute modifier + proficiency bonus + bonuses + penalties

Degrees of Success

Natural 20/1 Rule

• Natural 20: Improves result by one degree of success
• Natural 1: Worsens result by one degree of success

Proficiency Ranks & Bonuses

Bonuses and Penalties

Bonus Types (Use Highest of Each Type)

• Circumstance bonuses
• Status bonuses
• Item bonuses

Penalty Types

• Typed penalties: Use worst of each type
• Untyped penalties: All stack together

Special Check Types

Flat Checks

• Roll: d20 only, no modifiers/bonuses/penalties
• Auto-succeed: DC ≤ 1
• Auto-fail: DC ≥ 21

Secret Checks

• GM rolls for the player
• Result not revealed to player
• Fortune/misfortune effects still apply if player knows check occurs

DC from Modifier

Formula: 10 + total modifier for that statistic

Attack Rolls

Melee Attack Roll

d20 + Strength modifier (or Dexterity for finesse) + proficiency bonus + modifiers

Ranged Attack Roll

d20 + Dexterity modifier + proficiency bonus + modifiers

Spell Attack Roll

d20 + spellcasting attribute modifier + proficiency bonus + modifiers

Multiple Attack Penalty

Rules

• Penalty applies only during your turn
• Calculate based on weapon used for that attack
• Does not apply to reactions taken on other creatures' turns

Range Penalty

Example

120-ft rifle:

• At 240+ ft: -2 penalty
• At 360+ ft: -4 penalty
• At 720+ ft: -10 penalty (sixth increment, maximum range)

Defenses

Armor Class (AC)

10 + Dexterity modifier (capped by armor) + proficiency bonus + armor bonus + modifiers

Saving Throws

All saves use: d20 + attribute + proficiency bonus + modifiers

Save DC

10 + total modifier for that save

Basic Save Results

Perception Check

Formula

d20 + Wisdom modifier + proficiency bonus + modifiers

Uses

• Determines awareness
• Sets initiative order
• Notices hidden creatures or objects
• Searches for clues

Damage System

Five-Step Damage Process

1. Roll damage dice (weapon/spell determined)
2. Add attribute modifier
   • Melee: Strength
   • Thrown: Full Strength
   • Propulsive: Half Strength
   • Spells: Typically no modifier
3. Determine damage type
4. Apply immunities, weaknesses, resistances (in that order)
5. Reduce target's HP

Damage Types

Physical Damage

• Bludgeoning (B)
• Piercing (P)
• Slashing (S)

Energy Damage

• Acid
• Cold
• Electricity
• Fire
• Sonic
• Vitality (harms undead)
• Void (harms living)

Other Damage Types

• Force
• Spirit
• Mental
• Poison
• Bleed (persistent)
• Precision

Damage Modifiers by Attack Type

Melee Damage

Damage die + Strength modifier + bonuses + penalties

Ranged Damage

Damage die + bonuses + penalties

• Thrown weapons: Add full Strength modifier
• Propulsive weapons: Add half Strength modifier (rounded down)

Spell/Grenade Damage

Damage die + bonuses + penalties (no attribute unless noted)

Doubling and Halving Damage

Process

1. Roll normally with all modifiers
2. Double or halve the total
3. Round down when halving (minimum 1)

Immunity

Effects

• Complete negation of damage type or effect type
• Creatures still targeted but don't apply that effect
• "Immunity to critical hits": Converts double damage to normal (but other critical effects may apply)

Weakness

Effects

• Increase damage by weakness value
• Use highest weakness if multiple apply

Example

2d6 fire damage + weakness 5 to fire = 2d6+5 total damage

Resistance

Effects

• Reduce damage by resistance value (minimum 0)
• Use highest resistance if multiple apply

Example

Resistance 5 to fire reduces 7 fire damage to 2 damage

Hit Points and Dying

Hit Points (HP)

• Represent health and heroic drive
• Damage reduces HP on 1:1 basis
• Healing restores HP to maximum

Temporary HP

• Track separately from current/max HP
• Damage reduces temporary HP first
• Can only have one source of temporary HP
• Cannot be healed; only gained via new effects

Fast Healing and Regeneration

Fast Healing

Regains listed HP each round at beginning of turn.

Regeneration

• Regains listed HP each round at beginning of turn
• Prevents dying from exceeding death threshold
• Deactivates when taking specified damage type until end of next turn

Getting Knocked Out (Reaching 0 HP)

Non-Player Characters

Typically die immediately at 0 HP.

Player Characters

When reduced to 0 HP:

• Move initiative before their next turn
• Gain dying 1 condition, OR
• Gain dying 2 if knocked out by critical hit or critical failure on save
• If damage was nonlethal, become unconscious instead (without dying)

Dying Condition

Rule

Dying tracks death status with value 0-4. At dying 4, character dies.

Recovery Check (Start of Each Turn While Dying)

Flat check, DC = 10 + current dying value

Taking Damage While Dying

• Increase dying value by +1
• Increase dying value by +2 if from critical hit

Losing Dying Condition

• When dying reaches 0, remain unconscious at 0 HP
• Gain wounded 1 or increase wounded by 1 if already wounded
• Full recovery at 1+ HP automatically removes dying and unconscious conditions

Unconscious Condition

Effects

• Can't act
• Fall prone
• Drop held items
• -4 status penalty to AC, Perception, Reflex saves
• Gain blinded and off-guard conditions

Waking Up

If Unconscious from Dying

Wake only if restored to 1+ HP.

If Unconscious at 0 HP (Not Dying)

Naturally recover after 10 minutes to several hours.

If Unconscious with 1+ HP

Wake from:

• Taking damage (unless reduced to 0 HP)
• Receiving healing
• Being shaken (Interact action)
• Loud noise (Perception check against noise DC)
• Restful sleep

Wounded Condition

Gaining Wounded

• Gained when losing dying condition
• Stacks: Increase by 1 each time you lose dying

Effect on Dying

If you gain dying while wounded: increase dying value by wounded value

Removing Wounded

• Successful Treat Wounds activity
• Full HP + 10 minutes rest
• Decreases by 1 daily with full rest

Doomed Condition

Effect

Maximum dying value reduced by doomed value

Example

Doomed 1 = die at dying 3 instead of dying 4

Removal

Decreases by 1 after full night's rest

Death

Instant death if maximum dying value reaches 0

Heroic Recovery

Cost

Spend all remaining Hero Points (minimum 1)

Timing

At start of turn or when dying would increase

Effect

• Lose dying condition
• Stabilize at 0 HP
• Don't gain/increase wounded from this recovery

Death Effects

Rule

Spells/abilities with the death trait that reduce you to 0 HP instantly kill without reaching dying 4 first.

Massive Damage

Rule

Instant death if damage ≥ double your maximum HP in a single blow.

Actions System

Per Turn Resources

• 3 actions
• 1 reaction
• Free actions (no limit)

Action Types

Single Action

Brief, self-contained effect.

Symbol: One action icon

Activity

Multiple actions in succession. Must spend all at once. If interrupted, lose all committed actions.

Symbol: Two or three action icons

Reaction

• Uses 1 reaction
• Has a trigger
• Can occur any time trigger is satisfied
• Regains at start of your turn

Symbol: Reaction icon

Free Action

• No action cost
• With trigger: Acts like reaction
• Without trigger: Acts like single action on your turn

Symbol: Free action icon

Simultaneous Actions

Rule

Only one single action/activity/free action without trigger at a time.

Free actions with triggers and reactions can interrupt.

Subordinate Actions

Rule

Actions called within another action don't cost extra actions (cost already included).

• Retain normal traits and effects
• Modified as specified by parent action

Speaking

Cost

Requires no action

Limit

Can speak brief sentence (~1 per 6-second round)

Skill Actions

• Deception and persuasion require appropriate skill actions
• Speech has auditory trait

Exploration and Downtime Activities

Exploration Activities

• Have exploration or downtime traits
• Occur during non-encounter play
• Can perform other minor tasks alongside
• If interrupted: Lose time spent but no additional penalty

Common Exploration Activities

• Avoid Notice
• Detect Magic
• Scouting
• Searching
• Investigating

Downtime Activities

Measured in days:

• Repair/craft equipment
• Research spells
• Prepare for adventures
• Recover from injuries

Key Conditions Reference

Blinded

• Can't see
• Automatically fail Perception checks relying on sight
• -4 status penalty to Perception
• -4 status penalty to attack rolls

Broken

• Item can't function normally
• Doesn't grant bonuses
• Must be repaired to function

Concealed

• Harder to find and target
• Attackers must succeed DC 5 flat check or miss

Dying

• Unconscious
• At death's door
• Value 0-4; reaching 4 = death
• Attempt recovery check each turn (DC 10 + dying value)

Frightened

• Value indicates fear severity
• Penalty to checks/attack rolls equal to value
• Decreases by 1 at end of turn if no triggering effects

Hidden

• Observers unaware of location
• Can't be targeted directly
• Attacks get flat check
• Detected by successful Perception check or when attacking

Invisible

• Observers can't see you
• Treated as undetected
• Can't be targeted by attacks needing to see target
• Attack penalty based on concealment

Off-Guard

• Extra defense vulnerability
• Reduced AC
• Surprised creatures begin combat off-guard
• First attack against off-guard targets may gain advantage

Persistent Damage

• Recurs each round at end of turn
• After taking damage, attempt DC 15 flat check to recover
• Critical success/failure vs. attack roll doubles/halves damage like normal damage

Example: 1d6 persistent fire damage

Quickened

• Gain extra action each turn
• Extra action specified by effect granting condition
• Condition removes with effect end

Slowed

• Lose actions equal to value
• Value decreases by 1 at end of each turn

Unconscious

• Can't act
• Fall prone
• Drop items
• -4 status penalty to AC, Perception, Reflex
• Blinded and off-guard
• See detailed rules under "Unconscious Condition" section

Undetected

• Observers don't know you exist in area
• Can't be targeted
• Assumed position unknown
• Detected by successful Perception check or other means

Unnoticed

• Observers unaware of presence
• Treated as undetected to those unaware
• Observed by those who noticed you

Wounded

• Value tracks injury severity
• Gained when losing dying condition (value = 1 + previous wounds)
• If gain dying while wounded: increase dying by wounded value
• Removed by full HP + 10 minutes rest

Movement System

Speed

Defines movement distance per action.

Stride action moves up to Speed distance.

Basic Movement Actions

Movement Modes

Difficult Terrain

Effect

Costs extra movement (typically double).

Special Cases

Climbing, swimming, flying may cost extra based on specific terrain.

Forced Movement

Definition

Another creature moves you involuntarily.

Reactions

Forced movement triggered by attack doesn't trigger reactions based on movement except for Reactive Strike equivalents.

Cover

Effects

• Grants +2 circumstance bonus to AC
• Blocks line of effect for some effects

Types

• Lesser cover: +1 bonus
• Standard cover: +2 bonus

Flanking

Requirements

Two allies on opposite sides of enemy.

Effect

Each ally reduces enemy AC by 2 (no stacking).

Flat-footed condition represents exposed position.

Basic Actions (Partial List)

Interact one-action

Draw weapon, pick up object, open door, etc.

Leap one-action

• Jump distance up to 10 feet (horizontal) or 3 feet (vertical)
• Athletics check for longer jumps

Seek one-action

Attempt Perception to find hidden/undetected creatures or objects.

Sense Motive one-action

Read creature's intent. Perception or Insight check.

Step one-action

Move 5 feet without triggering reactions.

Stride one-action

Move up to Speed. Triggers reactions.

Strike one-action

Attack with weapon or unarmed attack. Compare result to target AC.

Spell System (Brief Overview)

Spell Attack Roll

d20 + spellcasting attribute + proficiency bonus + modifiers

Spellcasting Attribute

• Class spells: Key attribute (Wisdom for mystics, etc.)
• Innate spells: Charisma (unless stated otherwise)
• Focus spells: Specified in ability

Spell DC

10 + spellcasting attribute + proficiency bonus + modifiers

Used when spell requires saving throw instead of attack roll.

Hero Points

Gain

• 1 per session start
• Maximum: 3 Hero Points
• Reset: Each session

GM Awards

For heroic deeds:

• Selfless actions
• Daring feats
• Beyond normal expectations

Hero Point Uses

Use 1: Reroll Check

Cost: 1 Hero Point

Effect: Reroll check; use second result (fortune effect)

Not an action: Usable when unable to act

Use 2: Avoid Death

Cost: All Hero Points (minimum 1)

Timing: When dying would increase

Effect:

• Lose dying condition
• Stabilize at 0 HP
• Don't gain wounded from this recovery

Not an action: Usable when unable to act

Describing Heroic Deeds

Requirement

When spending Hero Point, describe how your character's:

• Deed
• Determination
• Remembered item

Enables the success or survival.

General Game Conventions

GM Has Final Say

Uncertain rules resolved by GM considering fairness and fun.

Specific Overrides General

Specific rules supersede general ones in conflicts.

Rounding

Round down unless specified.

Halved 1 = minimum 1.

Multiplying

Multiple multipliers combine (each after first adds 1 less):

×2 and ×2 = ×3

Duplicate Effects

Only highest level/rank effect applies.

Newer effect if equal rank.

Ambiguous Rules

If interpretation seems too good/problematic, collaborate with group on sensible solution.

Key Mechanics Summary

Checks

d20 + modifiers vs. DC

Degrees of success matter.

Combat

• Initiative determines order
• 3 actions + 1 reaction per turn

Damage

1. Apply modifiers
2. Determine type
3. Reduce by immunity/weakness/resistance
4. Subtract HP

Dying

• Recovery check each turn (DC 10 + value)
• Value 4 = death
• Wounded gained when exiting dying

Actions

• Single action
• Activity (multi-action)
• Reaction
• Free action
• Activities disruptable

Defenses

• AC: 10 + Dex + proficiency + armor + modifiers
• Saves: Fortitude/Reflex/Will
• Basic save: Results by degree of success

Movement

• Speed-based
• Stride triggers reactions
• Step doesn't trigger reactions
• Terrain modifies movement cost

Summary

Chapter 8 provides the complete mechanical framework for playing Starfinder 2E, from the fundamental d20 check system through complex combat mechanics, dying rules, conditions, and movement. The three modes of play (encounter, exploration, downtime) structure gameplay, while the action economy (3 actions + 1 reaction) provides tactical depth. The dying system creates dramatic tension with recovery checks and the wounded condition tracking cumulative injury. Hero Points offer narrative control and dramatic saves from death. Combined with clear damage resolution, comprehensive condition effects, and detailed movement rules, these mechanics create a robust and engaging play experience.