Skill Check Cheat Sheet

Quick reference for core skill-rolling mechanics and the skill list (Mongoose Traveller 2e Core Rulebook, 2022 Update — sourced via the Core Rulebook in NotebookLM). See also the Combat Cheat Sheet, Spaceship Operations Cheat Sheet and World Codes Cheat Sheet.

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The Core Roll

2D + Skill Level + Characteristic DM + other DMs ≥ Target Number

• Default target is 8+ (Average). Roll 2D6, add your skill level and the relevant characteristic DM, plus any situational modifiers.
• The referee picks which characteristic pairs with the skill for the situation (e.g. shoot a gun = Gun Combat + DEX; repair a gun = Gun Combat + EDU).
• A characteristic check uses only the characteristic DM (no skill).

Task Difficulty

Difficulty	Target
Simple	2+
Easy	4+
Routine	6+
Average	8+ (default)
Difficult	10+
Very Difficult	12+
Formidable	14+
Impossible	16+

If no difficulty is stated, assume Average (8+).

Characteristic DM

Score	DM
0	−3
1–2	−2
3–5	−1
6–8	+0
9–11	+1
12–14	+2
15+	+3

Skill Levels & Untrained

• No skill at all → DM−3 (untrained penalty).
• Skill 0 = trained but inexperienced: no bonus, but avoids the −3 penalty.
• Skill 1+ = +1 per level. (2–3 skilled professional; 4–5 renowned.)
• Jack-of-All-Trades reduces the −3 untrained penalty by 1 per level.

Effect = Total Roll − Target Number

Effect	Result
−6 or less	Exceptional Failure
−2 to −5	Average Failure
−1	Marginal Failure (may scrape through at a cost)
0	Marginal SUCCESS (barely, often with a condition)
1 to 5	Average Success
6+	Exceptional Success

⚠️ Effect 0 is a success, not a failure. Effect also doubles as combat damage.

Boon & Bane

• Boon (help, good tools, favourable): roll 3D, drop the lowest.
• Bane (poor tools, dim light, hindrance): roll 3D, drop the highest.
• Only one per check. A Boon + a Bane cancel out. Multiple Boons (or Banes) still count as one.

Opposed Checks

Both sides make their checks; highest Effect wins. A tie = standstill (no one gains advantage; try again or events move on).

Task Chains (sequential or assisting)

The Effect of one check feeds a DM into the next. Helpers assisting the same task use this same table to modify the lead character’s check (no separate flat bonus).

Previous Check	DM to Next
Fail, Effect −6 or less	−3
Fail, Effect −2 to −5	−2
Fail, Effect −1	−1
Success, Effect 0	+1
Success, Effect 1 to 5	+2
Success, Effect 6+	+3

Multiple Tasks at Once

Each additional simultaneous task raises the difficulty of every task by one level (e.g. Average → Difficult).

Timeframes

A task takes 1D × time unit (unit set by the task): seconds → combat rounds → ×10 seconds → minutes → ×10 minutes → hours → ×4 hours → ×10 hours → days.

• Go faster: one step up the table for DM−2.
• Go slower: one step down for DM+2.
• Only one step in either direction.

No “Rule of 6”

There is no auto-success on a natural 12 or auto-fail on a natural 2 in normal play — only the total vs. target matters. Extreme outcomes come from Effect, not the dice faces. (Natural-roll exceptions exist only in character creation: a natural 2 on Survival always fails; a natural 12 on Advancement forces you to stay in the career.)

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Skill List

Most skills have specialties — chosen when you reach level 1 in a skill with two or more. The bonus applies only to that specialty; other uses of the skill stay at DM+0.

Combat

• Gun Combat — ranged weapons (archaic, energy, slug)
• Heavy Weapons — launchers, artillery, vehicle-mounted (artillery, portable, vehicle)
• Melee — hand-to-hand (unarmed, blade, bludgeon, natural)
• Tactics — squad/fleet planning (military, naval)
• Leadership — directing and rallying allies
• Explosives — demolitions and bombs

Spacecraft & Vehicles

• Astrogation — plotting jumps (planetside = Navigation)
• Navigation — planetside course-plotting
• Pilot — spacecraft (small craft, spacecraft, capital ships)
• Flyer — atmospheric vehicles (airship, grav, ornithopter, rotor, wing)
• Drive — ground vehicles (hovercraft, mole, track, walker, wheel)
• Seafarer — watercraft (ocean ships, personal, sail, submarine)
• Gunner — ship weapons (turret, ortillery, screen, capital)
• Engineer — spacecraft systems (m-drive, j-drive, life support, power)
• Mechanic — general repair/maintenance
• Vacc Suit — spacesuits, environmental suits, battle dress

Knowledge & Investigation

• Science — scientific specialties (archaeology, astronomy, biology, chemistry, …)
• Investigate — observation, forensics, analysis
• Recon — scouting, spotting (opposes Stealth)
• Medic — first aid to long-term care
• Electronics — comms, computers, remote ops, sensors

Social

• Admin — bureaucracy, paperwork
• Advocate — law, oratory
• Carouse — partying, social subterfuge
• Deception — lies and disguise (often opposed by Recon)
• Diplomat — formal negotiation
• Persuade — fast-talk, bargain, intimidate
• Broker — trade negotiation
• Streetwise — urban underworld (wilderness = Survival)
• Steward — service to nobles and high-passage travellers
• Gambler — games of chance; bonus to Benefit cash rolls

Physical & Outdoor

• Athletics — physical augmentation (dexterity, endurance, strength)
• Stealth — moving unseen (opposed by Recon)
• Survival — wilderness
• Animals — handling, training, veterinary

Arts & Other

• Art — performer, holography, instrument, visual media, write
• Language — one specialty per language (Galanglic, Vilani, Zdetl, …)
• Profession — earn a living (belter, civil engineering, hydroponics, …)
• Jack-of-All-Trades — reduces the unskilled DM−3 penalty by 1 per level