Campaign Info
Updated: 2026-02-26
Overview
This is a living, open-ended Dominion Campaign set in the disputed underhive zone known as Sump Sink-17 - a sprawling network of collapsed hab-blocks, polluted waterways, and forgotten industrial infrastructure sitting beneath Hive Primus. No fixed end date, no fixed player roster, the campaign persists as a shared setting that gangs move through, leaving their mark on the hive as they rise, fall, recruit new blood, or disappear entirely.
The campaign supports any number of active players - it works well with as few as 2 and scales comfortably to 8 or more. Players can join, leave, and return mid-campaign without disrupting the game. It runs at a pace of approximately one battle per player per fortnight, arranged between players at their own convenience.
The Living Setting: Sump Sink-17
Sump Sink-17 is divided into three Zones, each with its own flavour, territory types, and special rules. The Zones represent different depths and dangers within the underhive.
Zone 1 - The Sprawl (Upper Underhive): Hab ruins, gang territories, black markets. Relatively safe. Rich in loot but fiercely contested. This is where new gangs establish themselves.
Zone 2 - The Drowned District (Mid Underhive): Partially flooded tunnels, rogue industrial machinery, toxic spills. Higher risk, higher reward. Experienced gangs compete here.
Zone 3 - The Sump (Deep Underhive): Near-lawless. Mutant warrens, ancient vaults, and things that should not be disturbed. Only the most powerful gangs venture here - and not all return.
Campaign Structure
The Cycle System
The campaign runs in fortnightly Cycles - each Cycle lasts two weeks, regardless of how many battles have been played. This gives all players a fixed window to arrange their games. A player who plays twice in a Cycle simply accumulates more post-battle actions within that window.
A Cycle ends at the close of the fortnight. At the end of each Cycle:
- Income & Upkeep is collected
- Territory Control is updated on the map
- The Arbitrator Event is rolled or chosen (one per Cycle)
- Gang ratings are recorded in the campaign log
There is no predetermined number of Cycles. The campaign continues as long as players are engaged.
Campaign Phases
The campaign is split into two phases:
Occupation (Cycles 1–5): Gangs expand into unclaimed territory. Each gang may claim one unclaimed territory per Cycle by playing a scenario against Arbitrator-controlled opposition (Smash & Grab). Gang-vs-gang battles still happen during Occupation for XP, income, and reputation - but territory cannot be taken from another gang during this phase.
Takeover (Cycle 6+): Any remaining unclaimed territories become Contested Zones. Full Challenging for Territory rules apply - gangs fight each other directly for territory control.
Joining & Leaving the Campaign
New Players Joining
A new gang can join at the start of any Cycle. They begin with:
- 1,000 credits to build their gang (standard Dominion starting value)
- D3+1 Territory tiles drawn randomly from the Sprawl (Zone 1) only
- No Reputation - they start at the bottom of the pecking order
If joining mid-campaign where established gangs are significantly more powerful, the Arbitrator may award bonus starting credits based on the average Gang Rating of existing gangs:
| Average Gang Rating | Bonus Starting Credits |
|---|---|
| Under 1,200 | +0 |
| 1,200 – 1,600 | +150 |
| 1,601 – 2,000 | +300 |
| 2,001+ | +500 + one free Hired Gun for first 3 battles |
Players Going on Hiatus
Life happens. When a player needs to step away:
- Their gang enters Lockdown - territories are frozen, no income is collected, no challenges can be issued against them
- Lockdown lasts a maximum of 3 Cycles
- After 3 Cycles, if still absent, the gang becomes Abandoned (see below)
Abandoned Gangs
An abandoned gang’s territories become Contested Zones - any active gang can fight for them. Abandoned territories use a simplified scenario: Smash & Grab (standard Necromunda scenario). The winner claims the territory.
Returning Players
A returning player resumes from where they left off, with the following adjustment:
- For each full Cycle missed beyond the first, they receive +75 credits as a “recovery fund” (max +300)
- Retain any territories that were not lost through becoming Abandoned and being claimed by another gang
Territory & Dominion Rules
Use standard Dominion Campaign territory rules as the backbone, with the following modifications:
Territory Tiers
Each territory belongs to a Tier based on its Zone:
| Tier | Zone | Income Modifier | Pitch Black |
|---|---|---|---|
| 1 | The Sprawl | Base income | No |
| 2 | The Drowned District | Base income +50% | No |
| 3 | The Sump | Base income x2 | Yes |
Territory Limits
To prevent runaway leaders hoarding the entire map, gangs have a soft territory cap:
- Sprawl territories: No cap
- Drowned District territories: Maximum 3 per gang
- Sump territories: Maximum 1 per gang (at any time)
Holding more than the cap means the excess territories generate no income and may be challenged by anyone freely (no formal challenge required - any gang can attempt to take uncapped-excess territories).
Scaling the Map
The territory pool should grow with the number of active gangs. As a baseline, seed the map with 3 Sprawl territories per starting gang, 1 Drowned District territory per starting gang, and 1 Sump territory per 3 gangs (minimum 1). When a new gang joins mid-campaign, the Arbitrator adds D3 new Sprawl territories and (if there are now enough gangs to warrant it) 1 new Drowned District territory to unclaimed areas of the map.
Challenging for Territory
Formal challenges for held territories only apply from Cycle 6 onward (the Takeover phase). During the Occupation phase (Cycles 1–5), gangs claim unclaimed territory instead - see Campaign Phases below.
- Each gang may issue one formal challenge per Cycle
- Challenges must be directed at a gang that controls a territory the challenger does not already border on the map - unless the challenger is the lowest-rated gang, in which case they may challenge any bordering territory
- The lowest-rated gang always has the right to challenge regardless of adjacency (the underdog rule)
Balancing: The Bounty System
The primary anti-snowball mechanic. When a gang’s rating exceeds others significantly, they become Notorious and a Bounty is placed on them.
Note: In a two-gang campaign, the Bounty System still applies but the Arbitrator should lean more heavily on Cycle Events and NPC threats to keep things balanced, since there is no third party to collect bounties.
Bounty Thresholds
| Rating Differential vs. Lowest Gang | Bounty Level |
|---|---|
| 0 – 300 | No Bounty |
| 301 – 600 | Wanted - attackers gain +D6x10 credits on victory |
| 601 – 1,000 | Outlaw - attackers gain +D6x10 credits and 1 free advance for a fighter on victory |
| 1,001+ | Most Wanted - attackers gain +2D6x10 credits, 1 advance, and may steal one item from the Outlaw’s stash on a 4+ on victory |
Bounties are recalculated at the end of every Cycle.
Hired Muscle for the Underdog
The lowest-rated gang in the campaign may hire one Hanger-On or Hired Gun for free each Cycle after the first (returned at Cycle end, no ongoing cost). This represents desperate alliances and the underhive’s tendency to back the underdog.
Cycle Events
At the end of each Cycle, roll D6 or choose one of the following:
| D6 | Event |
|---|---|
| 1 | Guilder Crackdown - All Territory income is halved this Cycle as Guilder tax collectors move through the Sink. |
| 2 | Scavvy Incursion - A Scavvy warband attacks the weakest gang’s least-defended territory. A random available player or the Arbitrator runs the Scavvies. |
| 3 | The Market Opens - A rare item becomes available to all gangs at Trading Post this Cycle only (Arbitrator chooses the item). |
| 4 | Blood Sports Season - All gang members who participate in a battle this Cycle earn +1 XP bonus regardless of outcome. |
| 5 | Tunnel Collapse - One Zone 2 territory (chosen randomly) is destroyed. Its holder loses it; it becomes a new Contested Zone next Cycle. |
| 6 | Arbitrator’s Choice - The Arbitrator introduces a narrative event of their own design. |
Narrative Arcs
Every 5 Cycles except the first, the campaign enters a Narrative Arc - a multi-battle storyline that all gangs are drawn into. These arcs give the campaign momentum and world-building without requiring a fixed endpoint.
Contamination: At each arc boundary, the underhive’s contamination levels rise - zones become more dangerous, battlefield conditions worsen, and the map itself changes. See The Deepening for the full escalation system.
Arc I - The Awakening (Cycles 1–5)
Backdrop: Sump Sink-17 has been quiet for decades. Now, something has disturbed the deep levels. Strange machinery has been heard running. Servitor-things walk in the dark. The gangs are just trying to establish themselves - but the Sink has other plans.
Arc Climax Battle (end of Cycle 5): The Signal - A multi-gang scenario. A mysterious homing beacon is active deep in the Drowned District. All gangs may participate. The gang that controls the beacon at battle’s end learns something about what lies in the Sump - and claims a special Relic Territory.
Arc II - The Power Play (Cycles 6–10)
Backdrop: Word has reached the upper hive. A Guilder caravan carrying rare STC fragments is passing through the Sink. Every gang, every scavenger, and every desperate soul in the underhive wants a piece. Alliances form and fracture overnight.
Arc Climax Battle (end of Cycle 10): The Caravan Run - A pursuit scenario across multiple terrain boards if possible. The caravan moves. Gangs intercept. Betrayals are encouraged.
Arc III - The Deep Reckoning (Cycles 11–15)
Backdrop: Whatever was sleeping in the Sump has woken up. Zone 3 becomes dramatically more dangerous. An ancient Clan House vault has been located - but the way is guarded by something inhuman. The dominant gang will need allies (or hostages) to breach it.
Arc Climax Battle (end of Cycle 15): The Vault - A cooperative/competitive scenario. All gangs must fight their way through a Horrors of the Underhive gauntlet. The first gang to reach the vault claims its treasure - but must survive the way out while all other gangs try to stop them.
Arc IV - The Last Descent (Cycles 16-20)
Backdrop: The contamination is nearing its peak. The Sump has reached Contamination 5 - the maximum - and the Drowned District and Sprawl are close behind. The ancient machinery deep beneath the Seep is groaning, cycling, building toward something. Every gang feels the pressure: the air is toxic, the water is rising, and the things in the dark are everywhere. There is nowhere safe left in Sump Sink-17. The only option is to push deeper.
Arc Climax Battle (end of Cycle 20): The Last Light - A multi-gang scenario in the Sprawl. The final lumen-shrine in the upper underhive fails. Gangs fight to salvage its power core before the Sprawl goes dark permanently. The winner claims a portable lumen-rig (grants immunity to Pitch Black in one battle per Cycle) and a territory bonus.
Arc V - The Turning (Cycles 21-25)
Backdrop: All three zones are at or approaching Contamination 5. The Seep is open - black water rises from the lowest point of Sump Sink-17, and with it come things that should have stayed buried. Ancient machinery has been detected beneath the Seep, still functional after millennia. If it can be activated, the tide might turn. Every gang knows what is at stake.
Arc Climax Battle (end of Cycle 25): Sealing the Seep - The repeating peak scenario. All gangs fight their way to the lowest point of the Sump and race to activate ancient machinery that will reverse the contamination. The winner gains the Seep-Wright title and shapes the recession. See The Deepening for full scenario rules.
Arc VI+ - The Receding (Cycles 26+)
Backdrop: The machinery beneath the Seep grinds to life. The black water begins to drain. The fog lifts. The creatures retreat into the deeper dark. Contamination levels drop at each arc boundary, mirroring the rate at which they rose. Zones that were reclassified revert as contamination falls below their thresholds - the Drowned District loses Pitch Black, the Sprawl dries out.
The Receding is not peace. Gangs fight over recovering territories, exploit the shifting power dynamics, and prepare for what comes next. Because the cycle repeats: once contamination returns to its starting values (Sump 1, District 0, Sprawl 0), the next arc boundary begins a new Deepening. The underhive breathes in, breathes out, and the gangs adapt or die.
See The Tidal Cycle for the full contamination schedule across both phases.
Fortnightly Rhythm
The campaign runs on a two-week Cycle cadence:
| When | What Happens |
|---|---|
| Ongoing | Players arrange battles at their convenience - aim for at least 1 per Cycle |
| End of Cycle (fortnight) | Arbitrator updates territory map, collects income records, rolls Cycle Event |
| Every 5th Cycle | Narrative Arc climax scenario announced with 1 Cycle’s notice |
| Anytime | New players may be inducted, returning players resume |
Campaign Record Keeping
The Campaign will be tracked on Munda Manager.
House Rules Summary
| Rule | Detail |
|---|---|
| Any Player Count | Campaign scales from 2 to 8+ gangs; map grows as players join |
| Territory Cap | Zone 2 max 3, Zone 3 max 1 per gang |
| Map Scaling | 3 Sprawl + 1 Drowned District territory per starting gang; new territories added when players join |
| Bounty System | Anti-snowball escalating rewards for defeating dominant gangs |
| Underdog Hire | Lowest-rated gang gets one free Hired Gun per Cycle |
| Lockdown | Absent players’ gangs frozen for up to 3 Cycles |
| Joining Mid-Campaign | Bonus starting credits scale with average gang rating |
| Cycle Events | One random event per Cycle keeps the setting alive |
| Campaign Phases | Cycles 1–5 = Occupation (claim unclaimed territory, no gang-vs-gang takeovers); Cycle 6+ = Takeover (fight for held territory) |
| Narrative Arcs | Every 5 Cycles a climax scenario drives the story forward |
| The Deepening | Cyclical zone contamination (0-5) drives battlefield hazards, income shifts, and zone reclassification; contamination rises, peaks, and recedes in a tidal cycle |
A Note on the Spirit of the Campaign
This campaign is designed to tell stories, not crown champions. A gang that gets wiped out and rebuilds from nothing is as much a part of the setting as the dominant power. Write down what happens to named fighters. Remember the betrayal in Cycle 3. Let the map tell a story.
The campaign ends when the players decide it ends - or when the next one begins.
Welcome to Sump Sink-17. Watch your step.