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+# THE CUSTODIANS — GM screen
+
+> Every number on this page was checked against `rules.mjs` on 9 September 2026
+> — 58 of 58 figures, by running the functions — not read out of the design
+> specs. Where this and `design/`
+> disagree, **the code is right and this page is stale** — `rules.mjs` is the
+> single authority, imported by both the runtime and the pack builder so that
+> packs cannot be built under one rule and played under another.
+
+## How to read this
+
+This is the sheet to have open while running, not the rules text. It carries the
+figures you reach for mid-scene and nothing you can look up afterwards.
+
+### Where these numbers live
+
+| what | file |
+| --- | --- |
+| every pure rule formula, and rolling, banding and grading | `rules.mjs` |
+| the six specs in `design/` | review history addressed to Codex — **not** current rules |
+
+## Rolling
+
+### The order of operations
+
+Difficulty multiplies the rating **first**, then situational modifiers add.
+
+| difficulty | rating becomes |
+| --- | --- |
+| Easy | × 2 |
+| Average | unchanged |
+| Difficult | ÷ 2, rounded down |
+
+Then add circumstance and any other modifier. The result is clamped to 1–100, so
+nothing is ever truly impossible or certain. A skill with a printed base of 5 or
+more never drops below 5.
+
+### The circumstance ladder
+
+Applied after difficulty. **Capped at ±40 in total**, however many apply.
+
+| | |
+| --- | --- |
+| Overwhelming | +30 |
+| Favourable | +20 |
+| Slightly good | +10 |
+| Neutral | 0 |
+| Slightly bad | −10 |
+| Unfavourable | −20 |
+| Severe | −30 |
+
+### Reading the roll
+
+From the effective chance, call it **B**:
+
+| band | is |
+| --- | --- |
+| Critical | `ceil(B / 20)` or less |
+| Special | `ceil(B / 5)` or less |
+| Success | B or less |
+| Fumble | `101 − ceil((101 − B) / 20)` or more |
+
+Fumble is tested **first**. **96–99 never succeed**, whatever the chance. 00
+always fumbles.
+
+Against armour: a **critical ignores armour entirely**; a **special counts it as
+half**, rounded down.
+
+## Reaction — who goes first
+
+Reaction runs on two axes and takes the better of them:
+
+- **Reflex** = `ceil(DEX / 3)`
+- **Awareness** = `ceil(Readiness / 10)`
+
+Base = `3 × max(Reflex, Awareness)`, then a d6 and a modifier capped at ±3.
+Marksmanship style is the agent's own choice — home worlds are gone, and nothing
+determines it for them.
+
+## The combat round
+
+### Defending
+
+Every defence after the first in a round is cumulative **−30%**. Two defences is
+−60%, three is −90%. Standing in front of three people is possible and stupid.
+
+### Fire modes
+
+| mode | to hit | gives you |
+| --- | --- | --- |
+| Slow | +10 | reloads |
+| Single | 0 | — |
+| Fast | 0 | a second shot |
+| Rapid | 0 | bursts |
+| Beam | +5 | sustain |
+
+A weapon with no mode set behaves as Single.
+
+### The second shot
+
+**−20% to both shots**, not just the second. The cost of hurrying is that you
+hurried the first one too — which is what stops this being a free extra attack
+for anyone holding a revolver.
+
+### Bursts
+
+| burst | rounds | to hit |
+| --- | --- | --- |
+| Short | 3 | −10 |
+| Long | 6 | −20 |
+| Full | 10 | −30 |
+
+Hits are **capped, not proportional**:
+
+| | success | special | critical |
+| --- | --- | --- | --- |
+| Short | 1 | 2 | 3 |
+| Long | 2 | 4 | 5 |
+| Full | 3 | 5 | 7 |
+
+However many rounds connect, **a burst is one wound event** — one Major Wound
+check, not one per round. Every round in the burst leaves the weapon regardless
+of what hits. A failure or fumble connects with nothing.
+
+### Range
+
+| band | to hit |
+| --- | --- |
+| Short | 0 |
+| Medium | −10 |
+| Long | −30 |
+| Extreme (to twice long) | −50 |
+| Beyond | cannot be attempted |
+
+### Two weapons
+
+−20% main hand and −40% off hand; if trained, −20% to both.
+
+## Damage and wounds
+
+### Hit points
+
+`HP = ceil((CON + SIZ) / 2)` — standard BRP.
+**Major Wound = `ceil(HP / 2)`**: a single blow of half your hit points or more.
+
+### The damage modifier
+
+From STR + SIZ:
+
+| STR + SIZ | modifier |
+| --- | --- |
+| up to 8 | −1d6 |
+| 9–16 | −1d3 |
+| 17–24 | 0 |
+| 25–32 | +1d3 |
+| 33–40 | +1d6 |
+| 41–50 | +2d6 |
+| 51–60 | +3d6 |
+| 61–70 | +4d6 |
+| 71+ | +`4 + ceil((total − 70) / 10)`d6 |
+
+### Hit locations (1D20)
+
+| melee | ranged | location | share of HP |
+| --- | --- | --- | --- |
+| 1–4 | 1–3 | Right leg | 42% |
+| 5–8 | 4–6 | Left leg | 42% |
+| 9–11 | 7–10 | Abdomen | 42% |
+| 12 | 11–15 | **Chest** | 50% |
+| 13–15 | 16–17 | Right arm | 35% |
+| 16–18 | 18–19 | Left arm | 35% |
+| 19–20 | 20 | **Head** | 40% |
+
+Ranged fire favours the chest, melee the legs — the two columns are different
+distributions, not one table read twice.
+
+A location's own pool is that share of total HP, rounded up. At its maximum the
+location is **disabled**; at twice its maximum, **destroyed**. Location damage
+folds together with Major Wound effects additively: both are true about the same
+body at once.
+
+### The Major Wound table (1D10)
+
+| d10 | wound | what it does |
+| --- | --- | --- |
+| 1 | Concussed | −20% to everything |
+| 2 | Winded | −20% physical, and you lose your action |
+| 3 | Bleeding | 1 HP at the end of each round |
+| 4 | Manipulation | −30% manipulation |
+| 5 | Mobility | −30% physical, MOV halved |
+| 6 | Deep bleeding | 2 HP at the end of each round |
+| 7 | Sensory | −40% perception, and −40% manipulation (sight) or communication (hearing) |
+| 8 | Broken | −30% manipulation, or −30% physical and MOV halved |
+| 9 | Crippling | defence only, MOV 1 |
+| 10 | Catastrophic | unconscious, defence only, MOV 1 |
+
+Wounds **stack**: two concussions is −40%, and a Major Wound stacks with a
+shattered limb, because both are true about the same body. Where a wound splits
+two ways and the variant was never recorded, the harsher reading applies.
+
+### Bleeding
+
+| | per round | stopped by |
+| --- | --- | --- |
+| Bleeding | 1 | a successful First Aid, or Medicine at any difficulty |
+| Deep bleeding | 2 | a **Difficult** First Aid, or Medicine at any difficulty |
+
+Any one listed stop is enough. First Aid restoring hit points does not clear the
+wound — the bleed keeps running until something on that list lands.
+
+## Panic — the short track
+
+0 to 5, **upward**, minutes long: what is happening to you *now*.
+
+| | track | penalty |
+| --- | --- | --- |
+| Steady | 0 | — |
+| Rattled | 1 | — |
+| Shaken | 2 | −5% |
+| Losing it | 3 | −10% |
+| Overwhelmed | 4 | −20% |
+| Broken | 5 | −20%, and they break |
+
+Talking someone down: a success takes one point off, a special or critical takes
+two — and **a fumble puts one on**.
+
+## Coherence — the long track
+
+0 to 10, **downward**, campaign length: what knowing has cost you. Do not confuse
+the two tracks at the table.
+
+| band | from | all rolls | communication |
+| --- | --- | --- | --- |
+| Anchored | 8 | — | — |
+| Loose | 5 | — | −5% |
+| Adrift | 3 | −5% | −10% |
+| Unmoored | 1 | −10% | −20%, and −30% to the return |
+| Displaced | 0 | −20% | −30% — permanent |
+
+### What it costs
+
+| | |
+| --- | --- |
+| Fumbling a crossing | 1 |
+| Witnessing a paradox | 1 |
+| Using crossing tech | 1 |
+| Breaking local law | 1 |
+| Overstaying | 1 |
+| Meeting yourself | 2 |
+| Killing a duplicate | 3 |
+
+### Getting it back
+
+One point each: a debrief, a week of downtime, an anchor object.
+
+## The way home
+
+### The return clock
+
+Three steps. It is the *crossing* that gets harder, not the people — a cost the
+players can see coming.
+
+| steps | the return is at |
+| --- | --- |
+| 0 | — |
+| 1 | −10% |
+| 2 | −20%, **and Difficult** |
+| 3 | −30%, and Difficult |
+
+### Extraction
+
+| roll | completes? | clock |
+| --- | --- | --- |
+| Critical | yes | a step **back** |
+| Special | yes | — |
+| Success | yes | — |
+| Failure | yes | +1 |
+| Fumble | **no** | +1 |
+
+Nothing else takes damage from a bad extraction. Getting out badly does not hurt
+anyone on the causeway; it makes the next crossing harder.
+
+## Craft actions — the stations
+
+Every agent takes a station, each uses a skill somebody already has, and the
+round is one roll each in the normal reaction order. No vector arithmetic, no
+map — range is a band.
+
+| station | skill | does | heat |
+| --- | --- | --- | --- |
+| Helm | Pilot | changes the band | +1 |
+| Guns | Energy Weapon | damage | +2, and on a failure too |
+| Sensors | Computer Use | marks a target | — |
+| Engines | Engineering | sheds heat | −3 |
+| Damage control | Repair | hull | — |
+| Signals | Persuade | talking | — |
+| Medical | First Aid | the crew | — |
+| Anchor | Transposition | escape | +2 |
+
+### Heat
+
+Runs 0–10. **Loud from 4. Blind from 6. Slow from 8.**
+
+### Space range bands
+
+| band | to hit |
+| --- | --- |
+| Docked | 0 |
+| Knife | +20 |
+| Close | +10 |
+| Standoff | −10 |
+| Distant | −30 |
+| Gone | cannot be attempted |
+
+## The environment
+
+### Falling
+
+1d6 per 3 metres, to a maximum of 20 dice — reached at 60 metres, and nothing
+above that falls harder. **Fall damage ignores armour.**
+
+### Drowning and airlessness
+
+1 point per round. Caught unprepared, you hold your breath half as long.