ALTERNITY

Game Master Reference Screen

Based on Alternity 1998 Core Rules (TSR)

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The Action Check System

Every action is resolved by rolling a d20 and comparing the result to the character's Action Score.

Action Score = Relevant ability score divided by 2 (round up), modified by skill ranks.

When a Situation Die applies, add it to (bad) or subtract it from (good) the d20 result before comparing.

Success Levels

Result Threshold Level
Roll ≤ Action Score ÷ 4 AS ÷ 4 (round up) Amazing
Roll ≤ Action Score ÷ 2 AS ÷ 2 (round up) Good
Roll ≤ Action Score AS Ordinary
Roll ≤ AS + AS÷2 AS + AS÷2 (round up) Marginal
Roll > Marginal threshold Failure
Amazing Good Ordinary Marginal Failure

Quick Threshold Examples

Action ScoreAmazingGoodOrdinaryMarginal
62369
824812
10351015
12361218
14471421
16481624
18591827

Situation Dice

Positive situation (advantage): subtract the situation die from d20 roll.
Negative situation (disadvantage): add the situation die to d20 roll.
Difficulty StepSituation DieDirection
Easyd4Subtract from roll
StandardnoneRoll d20 only
Hardd4Add to roll
Toughd6Add to roll
Challengingd8Add to roll
Formidabled12Add to roll

Ability Scores

ScoreFull NamePrimary Use
STRStrengthMelee attacks, lifting, carrying
DEXDexterityRanged attacks, initiative, agility
CONConstitutionDurability points, endurance
INTIntelligenceKnowledge skills, FX (some)
WILWillFX powers, mental resistance
PERPersonalitySocial skills, leadership
Scores range 3–18. Action Score for most checks = ability ÷ 2 (round up). Skill ranks add directly to Action Score (+1, +2, +3, +4).

Opposed Checks

Both characters make action checks. Compare success levels. If levels tie, compare actual d20 rolls (lower wins). If still tied, the defender succeeds.

Action Check Roller


THRESHOLDS
Amazing ≤ 3   Good ≤ 5
Ordinary ≤ 10   Marginal ≤ 15
[ AWAITING ROLL ]

Quick Ability Roll

Enter an ability score to compute an Action Score and roll against it at Standard difficulty.

Durability Tracker

Stun = CON score  |  Wound = CON × 1.5 (round down)  |  Mortal = CON × 0.5 (round up)
Damage fills Stun first, then Wound, then Mortal. Reaching 0 Mortal = Dead.
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Status Thresholds

ConditionTriggerEffect
HealthyAll tracks fullNo penalty
Stun DmgStun < max-1 step penalty to all actions
WoundedAny Wound damage-2 step penalty; healing required
CriticalAny Mortal damage-3 step; incapacitated risk each phase
DeadMortal = 0Deceased

Initiative Tracker

Each character rolls d20 at the start of combat. Lowest roll acts first (Phase 1). 3 phases per round; actions depend on initiative result.

Add Combatant

Order of Action
Round 1 Phase 1/3

No combatants yet

Combat Sequence

#Phase Step
1GM announces start of round
2All combatants roll d20 initiative
3Phase 1 begins (lowest init roll acts first)
4Characters with high rolls can act in Phase 1
5Phase 2: remaining actions resolved
6Phase 3: final actions and reactions
7End-of-round effects (stun recovery, etc.)

Standard Actions

ActionNotes
AttackMake one attack (melee or ranged)
MoveMove up to full speed
SprintMove at double speed, no attack
Activate FXUse a psionic/mutation power
Ready/StowDraw or holster weapon
First AidTreat Stun damage (DEX check)
Dodge/Evade+1 step penalty to attacker
Take CoverDive behind obstacle

Called Shots & Modifiers

ModifierEffect
Called shot: torsoStandard, +1 step (d4 added to roll)
Called shot: limb+2 steps, disarm/cripple on Amazing
Called shot: head+3 steps, stun or unconscious on Amazing
Cover (light)+1 step to attacker's roll
Cover (heavy)+2 steps to attacker's roll
Concealment+1 step, target partially hidden
Point blank (<2m)−1 step (d4 subtracted)
Long range+1 to +3 steps depending on weapon
Two weaponsOff-hand: +2 steps penalty
Burst fire−1 step, uses extra ammo

Damage Types

Typed20 die codeTrack hit
s — Stune.g. d4s, d6sStun only
w — Wounde.g. d6w, d8wWound (overflow to Mortal)
m — Mortale.g. d4m, d6mMortal directly

FX — Special Abilities

FX Score = WIL (for psionic powers) or INT (for tech/mutation). Each power use costs FX Points. FX Points = WIL or INT score; recover fully after 8 hours rest. Using FX is an action check vs. FX Score.

Psionic Disciplines (Mindwalkers)

Biokinesis

Governing score: WIL  |  Body control
  • Invigorate:Restore Stun points to self or touched ally.
  • Body Control:Regulate own body functions: slow bleeding, resist toxins, endure extremes.
  • Accelerate:Temporarily boost STR or DEX for one action/round.
  • Heal:Restore Wound or Mortal points over sustained concentration (minutes).
  • Disease Resistance:Block pathogens, reduce severity of illness.

Clairsentience

Governing score: WIL  |  Expanded senses
  • Remote View:Perceive distant locations as if present; range scales with skill.
  • Sense:Detect hidden objects, living creatures, or strong emotions nearby.
  • Postcognition:Read psychic impressions from an object or location (past events).
  • Precognition:Brief flash of possible near-future; GM provides vague warning.
  • Combat Sense:+1 step bonus to initiative; detect ambushes.

Psychokinesis

Governing score: WIL  |  Force of mind
  • Telekinesis:Move objects without touching; lift = WIL modifier × 10 kg.
  • Pyrokinesis:Generate or control fire; deals d4m to d6m damage.
  • Electrokinesis:Discharge electricity; disrupts electronics; deals d6s + stun.
  • TK Shield:Deflect ranged attacks: +1 to +2 step penalty on attackers.
  • Concussion:Focused shockwave in an area; all targets take d6s damage.

Telepathy

Governing score: WIL  |  Mind-to-mind
  • Mind Link:Silent communication with willing target; range = WIL in km.
  • Empathy:Sense surface emotions; opposed WIL check for unwilling targets.
  • Mind Probe:Read surface thoughts; deeper memories require opposed WIL.
  • Dominate:Take control of target's actions; resisted by WIL check each round.
  • Mental Blast:Psychic attack: d6s Stun; Amazing = unconscious 1d6 rounds.

FX Rules Summary

RuleDetail
FX CheckRoll d20 vs. FX Score (= WIL or INT ÷ 2 + skill ranks)
FX Point Cost1–4 FX points per power use (higher effect = higher cost)
FX Points MaxEqual to governing ability score (WIL or INT)
RecoveryFull recovery after 8 hours rest; partial with short rest
Amazing successMaximum effect; sometimes bonus effect
FailureNo effect; FX points still spent
Overload (optional)Spend extra FX points for bonus to action score

Mutations (Moreaus & Altered Species)

Mutations are purchased with points during character creation. Positive mutations cost points; negative mutations grant bonus points. Physical mutations are generally visible; mental mutations may be hidden.
MutationTypeEffectCost
Enhanced STRPositive+2 to STR score2 pts
Natural ArmourPositiveReduce incoming damage by 23 pts
Claws/FangsPositiveNatural weapon: d4+STR mod melee2 pts
Enhanced SensesPositive+2 to PER-based awareness checks2 pts
RegenerationPositiveRecover 1 Stun per round automatically4 pts
Chameleon SkinPositiveBlend with surroundings: +2 to stealth3 pts
Psi TalentPositiveAccess one psionic discipline at 1 rank4 pts
Enlarged FormPositive+1 size step; +STR, easier to hit2 pts
Reduced CONNegative-2 to CON; fewer Durability points−2 pts
ConspicuousNegativeVisibly unusual; social penalties in human space−1 pt

Star Drive Setting — 2503 CE

Humanity colonised the stars using drivespace technology. The known sphere is ~25 light-years radius from Sol. Diverse factions compete for resources, ideology, and survival — especially as alien threats push inward from the Verge.

Human Stellar Nations & Factions

The Concord
Human Government | Interstellar Authority

The primary human interstellar body, formed to maintain order, enforce treaties, and manage exploration. Operates the Concord Marines and exploration ships. Relatively egalitarian but bureaucratic.

OrderMilitaryExploration
VoidCorp
Megacorporation | Stellar Nation

A massive corporate state with its own territory, military, and citizens (called "employees"). Pursues profit at all costs; rumoured to traffic in alien tech. One of the most powerful and ruthless factions.

CorporateRuthlessTech
Orlamu Theocracy
Religious State | Stellar Nation

A theocratic nation founded on the belief that drivespace is divine — the "Godweb". Deeply religious, values knowledge and spirituality. Has a strong military for self-defence. Suspicious of alien contact.

ReligionDrivespaceConservative
Rigunmor Star Consortium
Trade Alliance | Stellar Nation

Mercantile confederation focused on commerce, contracts, and profit. Less militaristic than VoidCorp; operates through trade agreements. Known for excellent merchants, brokers, and spies.

TradeNeutralMercantile
The Verge / Fringe Worlds
Frontier Region | Independent Systems

Sparsely populated systems beyond the main stellar nations. Home to independent settlers, refugees, outlaws, and alien contact. Default setting of many Star Drive campaigns. Dangerous but free.

FrontierIndependentDiverse

Alien Species

Mechalus
Allied Species | Cyborg Integration

Humanoid species with biological neural interfaces allowing direct connection to computers and networks. Peaceful and intellectual; allied with The Concord. Excel as hackers and engineers. Slightly unsettling to humans.

CyborgAlliedHacker
T'sa
Allied Species | Rapid Metabolism

Quick, energetic reptilian species with hyper-fast metabolism. Natural tinkerers and inventors. Sometimes exhausting to deal with, but excellent pilots and engineers. Allied with The Concord.

ReptilianFastInventive
Weren
Allied Species | Warrior Culture

Large, bear-like species with a deep warrior culture and code of honour. Physically powerful; value personal combat and loyalty. Allied with The Concord as heavy infantry. STR and CON bonuses.

WarriorHonourableStrong
Klicks
External Threat | Hostile Alien

Insectoid alien invaders from beyond known space. Communicate via clicks and chemical signals. Highly aggressive; organised in hive-like military formations. Primary combat threat in many Verge campaigns. Do not negotiate.

HostileInsectoidHive
Stoneburners
External Threat | Unknown Origin

Mysterious, poorly understood alien threat. Appear alongside Klicks incursions. Believed to use exotic physics weaponry. Very little confirmed intelligence; GM latitude for unknowable horror elements.

MysteriousDangerousUnknown

Technology Levels & Travel

Tech ItemNotes
DrivespaceFTL travel; 1–5 days per jump depending on drive class
Laser weaponsCommon sidearms; no ammo reloads (power cell)
Gauss riflesElectromagnetic projectile; standard military
Neural interfaceDirect brain–computer link (Mechalus natural)
Combat suitPowered armour; subtract 2–4 from damage
MedpatchAuto-apply; restores d4 Stun, stabilises Mortal
Ship ClassTypical Role
Fast FreighterTrade, smuggling, PC transport
ScoutExploration, Concord recon
FrigateLight military escort
DestroyerSystem patrol, anti-piracy
CruiserMajor fleet combat
CarrierFighter deployment, fleet flagship

GM Notes

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