Starfinder 2E GM Core - Chapter 4: Subsystems

Source: https://2e.aonsrd.com/rules/1124-chapter-4-subsystems

Last Updated: 2026-01-14

Overview

Chapter 4 of the GM Core provides detailed subsystems for expanding gameplay beyond standard combat encounters. These frameworks allow GMs to create deeper, more nuanced encounters.

Victory Points Framework

Core Concept: Victory Points (VP) track progress through complex obstacles using a standardized measurement system that can be adapted across multiple subsystems.

Naming Convention

GMs should select thematic names reflecting the subsystem's purpose—examples include Awareness Points, Influence Points, and Research Points—helping players connect mechanics to narrative.

Subsystem Structures

Accumulating Model: PCs gain VP toward a goal threshold. Opposition can also accumulate VP, creating dynamic competition rather than simple attrition.

Accumulating Rolls Table:

• Critical Success: 2 VP
• Success: 1 VP
• Critical Failure: -1 VP

Diminishing Model: PCs start with VP and lose them through failures, creating urgency. When all VP are exhausted, failure occurs.

Diminishing Rolls Table:

• Critical Success: +1 VP (if applicable)
• Success: No loss
• Failure: -1 VP
• Critical Failure: -2 VP

Multiple Point Systems: Track different VP types simultaneously—such as both Infiltration Points (objectives) and Awareness Points (opposition).

Setting Scale

Running Considerations

Vary skills and approaches to encourage creativity. Use timers to promote participation. Ensure all PCs have meaningful opportunities to contribute. Provide both easy and challenging options for different character builds.

Rewards

Subsystems resolved in one session typically award accomplishment XP. Longer-spanning subsystems grant XP at meaningful milestones.

Influence Subsystem

Purpose: A short-term social encounter system where PCs accumulate Influence Points during timed interactions with NPCs.

Key Feature: Every character has meaningful contributions through diverse skill options—"Because of the variety of Influence skill options...every character has something important to contribute."

Encounter Structure

Encounters divide into rounds (typically 15 minutes to 1 hour each). Each round, PCs can act once to either Influence or Discover.

NPC Stat Block Components

Essential Statistics:

• Perception modifier
• Will modifier
• Discovery DC (Perception check + skill check options)
• Influence Skills (listed by difficulty, lowest first)
• Influence Thresholds (VP targets with benefits)

Additional Elements:

• Resistances: Increase DC by +2 (or +5 for stronger)
• Weaknesses: Decrease DC by -2 (or -5 for stronger)

Sample Stat Block: Groovelock

Level 3 Ysoki Engineer (grouchy, remorseful)

• Perception: +9
• Will: +12
• Discovery DC: 18 Perception; 15 Piloting; 16 Society
• Influence Skills:
  • DC 16 Crafting (discussing repairs/salvage)
  • DC 16 Junker Lore
  • DC 20 Performance
  • DC 20 Piloting
  • DC 22 Diplomacy
  • DC 24 Deception

Thresholds:

• 4 IP: Access to junkyard
• 6 IP: Assistant introduction
• 8 IP: Full repair assistance

Resistance: Refuses credits (+2 DC for payment appeals)

Weakness: Values craftmanship and salvage (-2 DC for Crafting)

Setting DCs

Begin with the NPC's Will modifier as base DC, typically for Diplomacy. Adjust using standard difficulty modifiers. Skills better suited to the NPC's interests receive easier DCs; less effective approaches receive harder DCs.

Example: Base DC 22 (from +12 Will). Intimidation becomes DC 24 (hard adjustment). Relevant Lore becomes DC 12 (very easy adjustment).

Running Encounters

Let PCs drive pacing through creative skill use. Make NPCs feel distinct and reactive. Break monotony by rotating NPC availability. Structure encounters with narrative beats—meals, introductions, conclusions.

Experience Rewards

Influence encounters award XP equivalent to moderate combat encounters of the same level.

Research Subsystem

Purpose: Structured information-gathering where PCs accumulate Research Points under time pressure or rival competition.

Framework: PCs use the Research action during exploration to gain RP. As thresholds are reached, they unlock information, rewards, and complications.

Building Components

Library: The research location—could be databases, locations, social gatherings, or virtual spaces. Include hazards or encounters as complications. Place research checks throughout the environment.

Research Stat Block: Details the topic, thresholds, and rewards.

Research Topic Stat Block Structure

Research Checks: Listed with location/area, followed by skill options and DCs (lowest to highest).

Research Thresholds: Numbered RP requirements with escalating effects and rewards.

Sample Research: Sihedron Cannon (7th Level)

Locations with Checks:

• Aeon Locks: Max 5 RP (DC 23 Arcana/Occultism; DC 28 Thievery)
• Sabotaging Virus: Max 10 RP (DC 18 Lore; DC 23 Computers)
• Captive Scientist: Max 15 RP (DC 21 Deception/Intimidation; DC 23 Crafting)

Thresholds:

• 5 RP: Basic weapon information
• 10 RP: Server access discovered; virus references project
• 15 RP: Weaponization history revealed
• 20 RP: Scientist explains creation (requires DC 28 Diplomacy)
• 30 RP: Armor upgrade provided; admiral location revealed; combat encounter triggered

Chases Subsystem

Purpose: Cinematic pursuit encounters emphasizing narrative obstacles over raw Speed.

Mechanics: PCs roll checks to progress through obstacles; opposition moves at steady pace. PCs gain Chase Points per obstacle; once threshold is met, party advances.

Obstacle System

Chase Points: Obstacles require specific CP totals (typically 1 or 2 fewer than party size).

Success Table:

• Critical Success: 2 CP
• Success: 1 CP
• Critical Failure: -1 CP

Automatic Success: Some actions bypass rolls, typically granting 1 CP (2 for exceptional help).

Obstacle Example: Crowd

Chase Points: 3

Overcome: DC 15 Acrobatics/Athletics; DC 13 Society

Narrative: "Throngs of people...making it difficult to continue."

Building Chases

Guidelines:

• Short: 6 obstacles, 10–20 minutes
• Medium: 8 obstacles, 15–25 minutes
• Long: 10 obstacles, 20–30 minutes

DC Setting: Use simple DCs at proficiency ranks appropriate for party level. Provide one easy and one standard/hard option.

Shortcut Mechanics: Critical successes might reveal faster paths with fewer obstacles.

Chase Types

Chase Down: PCs pursue enemies. PCs act second. End when PCs catch enemies or reach enemy safety point.

Run Away: PCs escape. PCs act first. End at safe location or three obstacles ahead.

Beat the Clock: Overcome obstacles before round limit expires.

Competitive: Both sides race toward same objective.

Sample Obstacles by Environment

Underground:

• Crumbling Corridor (1st): DC 13 Acrobatics/DC 15 Crafting
• Fungal Grotto (1st): DC 15 Fortitude/DC 13 Survival

Urban:

• Chain Link Fence (1st): DC 13 Athletics/DC 15 Thievery
• Crowd (1st): DC 15 Acrobatics/Athletics/DC 13 Society
• Security Drone (1st): DC 14 Computers/DC 16 Stealth

Vehicle:

• Traffic Jam (1st): DC 13 Perception/DC 15 Piloting
• Construction Site (2nd): DC 17 Piloting/DC 13 Society

Wilderness:

• Rope Bridge (1st): DC 15 Acrobatics/DC 13 Crafting
• Rushing River (1st): DC 15 Athletics/DC 13 Survival

Running Chases

Provide vivid narration showing gap changes and environment effects. Announce default option DCs. Encourage tactical descriptions. Use visual aids like cards or tokens. After 3 rounds stuck, allow alternative paths.

Infiltration Subsystem

Purpose: Subtlety-focused encounters where PCs accumulate Infiltration Points while managing Awareness Points (opposition detection).

Core Mechanic: PCs overcome obstacles to complete objectives without triggering too many Awareness Points.

Building Infiltrations

Objectives: Broad goals requiring multiple obstacles. Can sequence multiple objectives. Offer more obstacles than required, allowing PC choice.

Objectives Completion: Once target Infiltration Points are earned, character advances to next objective. Infiltration succeeds when all PCs complete final objective.

Obstacles System

Infiltration Points: Character progress toward overcoming individual or group obstacles.

Success Table:

• Critical Success: 2 IP
• Success: 1 IP
• Failure: 1 AP (Awareness Point)
• Critical Failure: 2 AP

Automatic Help: Spells/items usually grant 1 IP (2 for exceptional benefit).

Obstacle Types:

• Individual: Each PC must earn required IP themselves
• Group: Party pools IP together

Sample Obstacles

Locked Door:

• IP: 1 (group)
• Overcome: Hard/Very Hard Athletics, Computers, Thievery

Security Checkpoint:

• IP: 2 (individual)
• Overcome: Standard/Hard/Very Hard Deception, Diplomacy, Stealth

Surveillance Camera:

• IP: 1 (group)
• Overcome: Standard/Hard Acrobatics, Computers, Stealth

Trap:

• IP: 3 (group)
• Overcome: Hard/Very Hard Thievery
• Special: Critical failure triggers trap

Awareness Points Mechanics

AP increases through:

1. Failed obstacle checks (1 AP; 2 on critical failure)
2. Time passage (1 AP per round)
3. Disruptive activities

Typical Thresholds for 10 IP objective:

• 5 AP: DCs increase by 1; complication occurs
• 10 AP: Complication occurs
• 15 AP: DCs increase by 2; complication occurs
• 20 AP: Infiltration fails

Thresholds adjust based on story requirements—typically 1 complication per 5 AP tier.

Complications

Unexpected problems triggered by critical failures, AP thresholds, or GM discretion. Common types: security encounters, alarms, environmental hazards, identification checks.

Example: Submit Identification

• Trigger: First time reaching 5 AP
• Overcome: Standard/Hard/Very Hard Deception, Computers, Crafting, Stealth
• Success: Credentials accepted or drone convinced to leave
• Failure: Security alerted (+1 AP)
• Critical Failure: As failure, +2 AP

Limitation: Aim for 2 complications per AP threshold maximum.

Opportunities

Optional activities providing benefits without Infiltration Points—passwords, reduced AP, lowered DCs. May carry risks.

Example: Smooth the Path

• Requirement: PC completed objective, others haven't
• Effect: Provides Following the Expert benefits or skill check on behalf of ally

Edge Points

Advantages earned through preparation or quick thinking. Spend to convert failure/critical failure to success. Some Edge Points apply only in specific circumstances.

Preparation Activities

Before infiltration, PCs conduct downtime activities to gain Edge Points. Limit preparation time and available activities. Careless preparation risks AP generation before infiltration starts. Most activities grant benefits only once.

Hacking Subsystem

Purpose: Computer access encounters allowing diverse party contributions through varied skills.

Philosophy: Untrained characters contribute through magic, social skills, and creativity.

Hacking Types

Simple Hacking: One access point, no vulnerabilities. Two-action activity. Allow up to 2 additional failures before countermeasure triggers.

Complex Hacking: Multiple rounds of action with various access points, vulnerabilities, and countermeasures.

Building Computers

Concept Development:

1. What does accessing accomplish?
2. What level?
3. Simple or complex?
4. Magical, technological, or hybrid?
5. Physical or remote access?

Computer Types:

• Tech: Hacked via Computers, Crafting, Thievery
• Magical: Hacked via Arcana, Nature, Occultism, Religion
• Hybrid: Both magical and tech traits; different access points available

Setting Statistics

Use hazard Disable DCs as baseline:

• Low DC vulnerability exploit: -1 DC to Hack
• High DC vulnerability exploit: -2 DC to Hack
• Elite DC vulnerability exploit: -3 DC to Hack

Penalties never reduce DC below the low threshold.

Notice vs. Disable:

• Notice DC: Lower (Perception-based)
• Disable DC: Higher or elite

Complex Hacking Structure

Access Points: Each has unique vulnerabilities and countermeasures. Listed as physical (adjacent) or remote.

Vulnerabilities: Skill checks to exploit, reducing Hack DC.

Countermeasures: Trigger after accruing failures. Some have persistent trait (retrigger each round until disabled).

Round Actions:

• Exploit vulnerabilities (lower DC)
• Notice and disable countermeasures
• Hack access point

Failure Tracking: Each failed check = 1 failure (2 on critical failure) per access point. When failures reach threshold, countermeasures trigger.

Idle Round Penalty: If PCs skip Hacking/countermeasure disabling in a round, they accrue 1 failure to associated access point.

Sample Vulnerabilities

• Deduce username/password (Perception, Society, Lore)
• Call customer service (Deception, Diplomacy)
• Steal/spoof authentication (Crafting, Thievery)
• Program keylogger (Computers, Performance)
• Find allied hacker (Diplomacy, Society)
• Survey server farm (Nature, Survival)
• Divination (Occultism, Religion)
• Bribe administrator (Diplomacy, Intimidation)
• Physical retrieval (Acrobatics, Piloting)
• Phishing scheme (Computers, Society)
• Phreak server (Crafting, Performance)
• Social engineering (Deception, Lore)
• Denial-of-service (Computers; Diplomacy/Performance to rally help)
• Ritual casting (Arcana, Nature, Occultism, Religion)
• Electromagnetic theft (Crafting, Piloting)
• Social infiltration (Deception, Society)
• Employee theft (Stealth, Thievery)
• Tower climbing (Acrobatics, Athletics)
• Biometric spoofing (Deception, Medicine)
• Hidden zone discovery (Piloting, Lore)

Sample Countermeasures

• Account banning (Notice: Computers/Perception; Disable: Deception/Intimidation)
• False information (Notice: Computers/Crafting/Perception; Disable: Stealth/Thievery)
• File deletion (Notice: Society/Survival; Disable: Computers/Crafting)
• Authentication lockout (Notice: Perception; Disable: Crafting/Thievery/Lore)
• Admin detection (Notice: Perception; Disable: Computers/Diplomacy/Intimidation)
• Security guard (Notice: Perception; Disable: Deception/Stealth)
• Hellknight tracker (Notice: Society; Disable: Stealth/Survival)
• Admin threat (Notice: Perception; Disable: Deception/Diplomacy/Intimidation)
• Magitech virus (Notice: Arcana/Occultism; Disable: Arcana/Occultism/Will save)
• First World curse (Notice: Perception; Disable: Nature/Survival)
• EMP strike (Notice: Perception; Disable: Athletics/Thievery)

Simplified Quick Hacking

Each party member rolls appropriate skill check supporting primary hacker. Each success lowers Hack DC by 1 (2 on critical success). Critical failure raises DC by 1.

Computer Stat Block Format

Access Point: Physical or remote, successes required, DC by skill (with minimum proficiency noted)

Vulnerabilities: Exploit DC and DC reduction value

Countermeasures: Failure threshold, countermeasure description, Notice DC, Disable DC

Critical Success: Extra benefits for exceptional success

Success: Standard computer functions and benefits

Additional Rewards

Hacking can yield financial gain (draining funds, stealing credentials), information (corporate secrets, evidence, magical formulas), and valuable contacts. Hint at these rewards through Recall Knowledge checks.

Cinematic Starship Scenes

Purpose: Encounter-mode starship combat using narrative roles rather than tactical grids.

Structure: Runs like standard encounters with initiative-based rounds. PCs occupy starship roles with specialized actions.

Scene Components

PCs' Starship: Details and available roles

Threats: Enemy starships, creatures, hazards, gravity wells

Victory Conditions: Scene objectives and success thresholds

Initiative and Roles

Initiative Roll: Based on selected starship role (Piloting for pilots, Computers for science officers, etc.). PCs receive Starship Bonuses based on role selection.

Role Selection: Each round begins with available roles announced. PCs select unoccupied roles (some roles allow multiples). PCs maintain role until round end. Role determines available special actions (typically 2-action activities).

Action Economy: PCs have 3 actions. Most starship actions require 2 actions, leaving 1 spare for Aid, guidance spells, or other actions.

Opposition: Threats operate preset routines; no crew actions.

Experience Values

Additional Considerations

Multiple Crew: Beyond baseline 4 PCs, examine VP success requirements and enemy output. More PCs provide options, not necessarily increased damage.

Character Abilities: Core class abilities (Aim, Suppressing Fire) aren't designed for cinematic scenes. Spells and feats are GM-discretionary based on appropriateness. Enhancement spells (guidance) fit well. Powerful spells might warrant bonuses instead of standard actions.

Persistent Damage on Starships: Resolves at round end (not per player turn). One PC rolls flat check to recover.

Conditions: Apply normally, adjusted for starship scale where appropriate.

Integration Across Subsystems

Subsystems combine effectively—chases during infiltrations, infiltrations preceding hacking objectives, vehicles in chases, cinematic starship scenes incorporating Victory Points. Designate one backdrop subsystem tracking longer-term progress, with shorter-term subsystems contributing to it.

This document contains the complete mechanical details from SF2E GM Core Chapter 4: Subsystems, including all frameworks, tables, DCs, sample stat blocks, and implementation guidelines for Victory Points, Influence, Research, Chases, Infiltration, Hacking, and Cinematic Starship Scenes.