THE CUSTODIANS

A Basic Roleplaying game of crossings, as a Foundry VTT system.

A drab British government agency deals with crossings. Reality keeps a record of what belongs where, and it can be made to get it wrong. Agents are civil servants: they carry warrant cards and cordon tape, they file in triplicate, and the thing that makes them dangerous is that they know how the record works.

The tone is bureaucratic horror. Most cases close with an arrangement rather than a fight, and the supernatural is a filing error somebody committed on purpose.

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Installing

In Foundry: Game Systems → Install System → Manifest URL

https://gitea.timevans.uk/slaguru666/RingBRP/raw/branch/main/system.json

Or by hand: clone this repository into your Foundry data directory as Data/systems/ringbrp, then restart Foundry.

git clone https://gitea.timevans.uk/slaguru666/RingBRP.git ringbrp

Requires Foundry v13+ (verified against v14.364). No modules are required. Dice So Nice works if you have it, using your own dice — the system ships no dice skins and does not touch anybody's dice settings.

Deploying to a remote Foundry server

The built compendia in packs/ are committed on purpose, so a remote server needs nothing but the files:

cd /path/to/foundrydata/Data/systems
git clone https://gitea.timevans.uk/slaguru666/RingBRP.git ringbrp
# restart Foundry

node_modules/ is not committed. You only need it if you intend to rebuild the packs or regenerate art on that machine:

npm install          # pulls classic-level, used to write the LevelDB packs
npm run build        # rebuilds packs/ from tools/content.mjs
npm run check        # the sixteen guards; the build refuses to run if they fail

To update a deployed server: git pull and restart Foundry. If the pull touches packs/, Foundry must be stopped first — LevelDB will not tolerate its files changing underneath a running server.

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What is in the box

Postings	25, each with a key characteristic, trained skills, talents and its own kit
Trades	10 ordinary jobs the department recruits from, plus induction
Catalogue	236 items — 123 gear, 62 weapons, 32 armour, 19 vehicles
Skills / talents	62 skills, 19 talents
Bestiary	47 statblocks across folklore, horror and the far side
Eras	modern, antique, future, anomalous — the agency is old and never abolishes anything
Icons	292, all generated from tools/icons.mjs; no external art
Starter scenario	BLACK PLATFORM, a six-player action starter, importable as a single Adventure
Compendia	pregens, NPCs, skills, weapons, armour, gear, vehicles, powers, tables, rules, the starter
Rules journal	13 pages, generated from rules.mjs so the book cannot drift from the code

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The rules, in brief

d100 roll-under, banding into critical / special / success / failure / fumble. 96–99 always fail, 00 always fumbles, and every skill has a 1% floor.

Reaction Lanes replace Strike Rank. Initiative is 3 × max(⌈DEX/3⌉, ⌈readiness/10⌉) less carried load, plus a d6, re-rolled every round — including the first, so the opening round is ordered like every other.

Coherence runs 10 → 0 and measures how well-filed an agent is in reality. It bands into Anchored / Loose / Adrift / Unmoored / Displaced, and spending it is how the supernatural works.

The Quiet Arts are deliberate misfilings, not spells. They cost Coherence, and they only ever arrive from a crossing that goes wrong.

Defences are graded. A defence stops a blow of its own quality or worse outright; against something better it only reduces it by as many steps as it was outclassed by. Only a critical stops a critical.

Access is a record. There is no hacking skill and nothing to break into — see below.

A weapon's fire mode is a decision. Slow weapons shoot better and then make you work; fast ones offer a second shot at the cost of both; rapid ones fire bursts; beams can be held on the target for damage instead of hits. A weapon that cannot fire a burst cannot be made to.

Sights and lamps apply themselves. A sight is graded by range band — a telescopic sight is a penalty inside ten metres — and a carried lamp buys the dark back to dim, never to daylight, and tells everyone where you are. Neither is a thing the player selects: both are facts about what is in the pack.

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Borrowed Authority — the access subsystem

Deliberately not cyberpunk. Nobody jacks into anything.

What an agent has is a named credential belonging to somebody real, with a scope of things that person could plausibly do, a Trust that erodes as it is used, and red flags describing how the real owner behaves.

• Inside its scope there is no roll. A facilities contractor opening a plant room is not intrusion, it is Tuesday. It costs 1 Trust and it works.
• One tier beyond is a stretch — roll, at −20 for each red flag you break. The system is not testing whether you are clever. It is testing whether you are behaving like the person whose name is on the record.
• Two tiers beyond is impossible at any skill. No percentage on any sheet gets a contractor issuing accounts.
• A fumble burns the credential, and somebody real is going to be asked about it.

A credential is assembled, not found: up to three dossier items, each a separate scene using a different skill, at most one of them at a keyboard. Items make the credential better, never the roll easier.

AI is a posture on the target rather than an opponent — a gatekeeper raises what counts as routine, an analyst writes a new red flag every time you stretch, an asset stands in for a dossier item.

And you may spend Coherence to widen a scope, because reality can be made to remember that the person always held that duty. It works. It always works. Push a credential past what its Trust will carry and your file and theirs converge one step, and nothing in this game spends anything to converge them back.

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Repository layout

ringbrp.mjs          the system: sheets, engine, hooks (~5,500 lines)
rules.mjs            THE SINGLE AUTHORITY for every rule formula
system.json          Foundry manifest
template.json        data model for every Actor and Item type
templates/           Handlebars sheets
styles/              one stylesheet
lang/en.json         all user-facing text
icons/  fonts/  art/     generated art
packs/               built LevelDB compendia (committed — see Deploying)
tools/
  content.mjs        the catalogue: skills, weapons, armour, gear, vehicles, NPCs
  build-packs.mjs    builds packs/ — runs the sixteen guards first and refuses on failure
  make-icons.mjs     draws all 231 icons
  rules-text.mjs     generates the rules journal FROM rules.mjs
  mission.mjs        the case generator
  mission-tables.mjs its content tables
  check-rules.mjs    guard: no rule may be defined twice
  check-kits.mjs     guard: every posting's kit must exist and be usable
  check-lang.mjs     guard: no localisation key may be both a value and a branch
  check-lethality.mjs guard: no creature may quietly change what it does to a party
  check-rollable.mjs guard: no clue may hide behind a roll nobody present can make
docs/REVIEW_LOG.md   the design and defect log, R-1 onward

The one rule this codebase enforces on itself

No rule formula may exist in more than one place. Everything lives in rules.mjs, and tools/check-rules.mjs fails the build if a formula is restated, if an alias stops being identity-equal to what it aliases, if a constant is re-declared as a literal, or if an exported rule has no spot-check. The packs used to be built under one set of numbers and played under another; this makes that impossible to ship.

The build runs all sixteen guards before it writes anything:

check-rules: OK — 110 rules, 46 files scanned, 3 aliases + 46 constant sets checked, 395 formulas verified
check-kits: OK — 25 roles, 10 trades, 218 catalogue items, every kit key resolves, every posting can use what it carries, every loadout distinct
check-lang: OK — en.json, 1018 keys, no leaf/branch collisions
check-templates: OK — 19 templates compile
check-behaviour: OK — 76 behavioural tests
check-scenarios: OK — 13 scenario files, 83 mechanic tags, every skill named resolves against 62 catalogue entries
check-rollable: OK — 82 rolls across 13 scenario files, every one reachable at 25% or better by somebody present
check-creatures: OK — 102 actor specs across 8 sources, every characteristic, skill, kit key, talent, species and style resolves, no duplicate keys
check-anatomy: OK — 5 body plans, 36 locations, d20 complete in both modes, every location drawn, every kind handled and destructible, 20 plan changes carried 432 wounds with their severity intact, 1 flyer(s) with a survivable landing
check-lethality: OK — 47 creatures, every one fighting exactly as recorded against the frozen party
check-focus: OK — focus fire measured against 31 packs, helps in all of them, 31 of them by more than their own noise
check-firstblood: OK — the first disabling blow is worth 40 points of wipe rate in the four-player cut, 15.4 in the six-a-side line
check-attackers: OK — three of the four-player cut disable on 11.1% of their attacks or better, and one of them on 0.1%
check-fight-tail: OK — a fight past 15 rounds wipes the party 1.4x as often in the four-player cut and 2.4x at six a side, and nothing was truncated
check-cited: OK — 23 cited figures across 13 scenario files resolve against 3 baselines
check-bestiary: OK — 47 creatures, the document matches the game