Core loop: describe → ask → decide → roll only when failure matters.
Table Flow
Describe what the characters perceive.
Ask: “What do you do?”
Clarify intent and method.
Decide: automatic, impossible, or roll.
Roll using the correct mechanic.
Resolve consequences and move the scene forward.
Never roll when both success and failure are boring.
Situation
Ruling
Easy, no pressure
Automatic success
Hard, risky, uncertain
Roll
No plausible method
Impossible unless approach changes
Good plan bypasses obstacle
Reward it; no roll or easier difficulty
Core Dice
Use
Roll
Success
Attack
1d20
Target number or higher
Saving throw
1d20
Save number or higher
Ability check
3d6 / 4d6 / 5d6
Total equal to or under ability score
Nonweapon proficiency
Ability check with difficulty shift
Relevant proficiency reduces difficulty one step
Thief skill
d100
Listed % or lower
Reaction
2d10
Higher is friendlier
Morale
2d10
Roll morale score or lower
Ability check: roll Xd6 by difficulty. Success if total ≤ ability score. No modifiers.
Ruling Matrix
Question
Use
Is the character attacking?
THAC0 attack roll
Is the character resisting harm?
Saving throw
Is it a trained thief task?
Thief skill
Is it a learned nonweapon skill?
Ability check; proficiency shifts difficulty down one step
Is it raw talent under pressure?
Ability check at fictional difficulty
Is there no meaningful risk?
No roll
Best ruling: fair, fast, consistent, and tied to the fiction.
Ability Uses
Ability
Use For
STR
Force, lift, bend, jump, grapple, break
DEX
Balance, dodge, stealth movement, reflexes
CON
Endure, fatigue, exposure, hold breath
INT
Reason, recall, search logic, puzzles
WIS
Notice, intuition, tracking, judgment
CHA
Persuade, command, deceive, perform
Do not add circumstance modifiers. Use fiction to set difficulty, then apply only the proficiency shift.
When to Roll
Handling
Failure is meaningful, interesting, or consequential
Roll ability check
No pressure, no danger, no real consequence
No roll
Good roleplay or clever method removes uncertainty
No roll or lower base difficulty
No plausible method
Impossible until approach changes
Ability Check System
Core mechanic: Roll a number of d6 equal to the difficulty. Compare the total to the relevant ability score. Success means the roll is equal to or under the ability score. Failure means the roll is over the ability score.
No modifiers. No additions. No advantage. No disadvantage. Just roll Xd6 and compare.
Difficulty Ladder
Difficulty
Dice
Use For
Standard
3d6
Reasonable challenge for a competent person; most checks live here
Hard
4d6
Stressful, risky, or requiring precision; failure likely for average scores
Extreme
5d6
Exceptional difficulty; use sparingly; even skilled characters struggle
Nonweapon Proficiencies
Situation
Rule
Relevant proficiency
Reduce difficulty by one step: Extreme → Hard, Hard → Standard
Standard + relevant proficiency + no pressure
Automatic success
No relevant proficiency and task requires training
Increase difficulty by one step
No relevant proficiency but ordinary task
No penalty
Optional expert-level proficiency
Reduce difficulty by two steps; use very sparingly
Setting Difficulty
Ask: “How hard is this in the fiction, before skills?”
Set Standard, Hard, or Extreme.
Then apply proficiency: relevant training shifts one step easier.
If the task reasonably requires training and the character lacks it, shift one step harder.
Roll only if failure matters.
Examples
Action
Base
With Proficiency
Without Proficiency
Climbing a wet wall
Hard, 4d6
Standard, 3d6
Hard, 4d6
Picking a lock
Hard, 4d6
Standard, 3d6
Extreme, 5d6
Persuading a guard
Standard, 3d6
Automatic if no pressure; otherwise Standard
Standard, or Hard if suspicious
Tracking in bad weather
Hard, 4d6
Standard, 3d6
Extreme, 5d6
Final intent: ability score + difficulty + proficiency shift. That is the whole system.
Party Combat Tracker
Editable. Use the buttons to add/remove rows. Saved locally in this browser.
Name
Class/Lvl
THAC0
AC
HP
Move
Saves/Notes
Attack roll needed = THAC0 − target AC − attack bonuses + attack penalties.
THAC0 Calculator
Example
Need
THAC0 20 vs AC 10
10+
THAC0 18 vs AC 5
13+
THAC0 16 vs AC 0
16+
THAC0 14 vs AC -2
16+
AC Converter
Quick conversion: Ascending AC = 20 − AD&D AC.
AD&D AC
Ascending AC
10
10
5
15
0
20
-5
25
-10
30
Ability Check Helper
Difficulty is set first from the fiction. Proficiency then shifts it. Standard with relevant proficiency and no pressure is automatic.
Resolve movement, missiles, spells, melee, and special actions.
Apply damage, saves, magic resistance, and ongoing effects.
Check death, morale, surrender, retreat.
Start next round.
Spellcasters hit before completion may lose the spell.
Round: about 1 minute; usually one meaningful action.
Attack & THAC0
Number needed = attacker THAC0 − target AC.
Example
Result
THAC0 18 vs AC 6
Need 12+
THAC0 18 vs AC 0
Need 18+
THAC0 14 vs AC -2
Need 16+
Modifier
Effect
Magic weapon, STR, rear attack
Bonus
Cover, darkness, range, bad footing
Penalty
Prone target in melee
Usually bonus
Firing into melee
Penalty/risk by ruling
Calculated THAC0 by Class Group
Group
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Priest
20
20
20
18
18
18
16
16
16
14
14
14
12
12
12
10
10
10
8
8
Rogue
20
20
19
19
18
18
17
17
16
16
15
15
14
14
13
13
12
12
11
11
Warrior
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Wizard
20
20
20
19
19
19
18
18
18
17
17
17
16
16
16
15
15
15
14
14
Use actual class group: Warrior includes fighter-type progression; Priest, Rogue, and Wizard use their listed progressions.
Saving Throws
Save Type
Use For
Paralyzation / Poison / Death
Venom, death magic, paralysis
Rod / Staff / Wand
Device magic
Petrification / Polymorph
Transformation, stone effects
Breath Weapon
Dragon breath, blasts
Spell
General spell resistance
Roll 1d20. Meet or beat the listed save number.
Use the most specific save first. If uncertain, use Spell.
Magic Procedure
Spell is memorised/prepared.
Declare spell.
Check range, target, sight, components.
Resolve initiative/casting time.
If hit or disrupted before completion, spell may be lost.
Apply saves, magic resistance, damage, duration.
Can caster speak?
Can caster gesture?
Is the material component ready?
Can target be seen/reached?
Surprise & Encounters
Are both sides aware?
If not, roll surprise.
Set encounter distance.
Describe what each side sees/hears.
Check reaction, morale, or immediate actions.
Situation
Modifier
Ambusher hidden and prepared
Victim penalty
Noisy armour / torchlight
Victim penalty
Alert scout / guard
Victim bonus
Silence / invisibility
Strong penalty
Do not roll surprise when one side clearly knows the other is there.
Reaction & Morale
2d10
Reaction
2–4
Hostile / attacks
5–7
Unfriendly / suspicious
8–13
Uncertain / cautious
14–16
Talkative / open
17–20
Helpful / friendly
Morale Triggers
First casualty.
Leader killed.
Half force down.
Outmatched by magic.
No escape.
Offered mercy or bribe.
Fanatics, undead, constructs, charmed creatures, and cornered foes may ignore normal morale.
Armor Values
Armor
AC
With Shield
None
10
9
Leather / Padded
8
7
Studded Leather / Ring Mail
7
6
Brigandine / Scale / Hide
6
5
Chain Mail
5
4
Splint / Banded / Bronze Plate
4
3
Plate Mail
3
2
Field Plate
2
1
Full Plate
1
0
Lower AC is better. Shield normally improves AC by 1.
Common Melee Weapons
Weapon
Type
Speed
Dmg S-M
Dmg L
Notes
Dagger
P
2
1d4
1d3
Throwable
Knife
P/S
2
1d3
1d2
Backup
Club
B
4
1d6
1d3
Common
Quarterstaff
B
4
1d6
1d6
Two-handed
Short Sword
P
3
1d6
1d8
Sidearm
Long Sword
S
5
1d8
1d12
Classic
Broad Sword
S
5
2d4
1d6+1
Reliable average
Bastard Sword, 1H
S
6
1d8
1d12
One-handed
Bastard Sword, 2H
S
8
2d4
2d8
Two-handed; no shield
Two-Handed Sword
S
10
1d10
3d6
Two-handed
Hand Axe
S
4
1d6
1d4
Throwable
Battle Axe
S
7
1d8
1d8
Heavy axe
Two-Handed Axe
S
9
1d10
2d8
Two-handed
Spear
P
6
1d6
1d8
Set vs charge
Footman’s Mace
B
7
1d6+1
1d6
Blunt
Horseman’s Mace
B
6
1d6
1d4
Mounted
Morning Star
B/P
7
2d4
1d6+1
Heavy impact
Warhammer
B
4
1d4+1
1d4
Fast blunt
Footman’s Flail
B
7
1d6+1
2d4
Flexible
Halberd
P/S
9
1d10
2d6
Polearm
Military Fork
P
7
1d8
2d4
Polearm
Partisan
P
9
1d6
1d6+1
Polearm
Ranseur
P
8
2d4
2d4
Polearm
Type: B = bludgeoning, P = piercing, S = slashing. Weapon speed is mainly used if your table uses weapon-speed initiative.
Missile Weapons
Weapon
ROF
Range S/M/L
Dmg S-M
Dmg L
Notes
Short Bow
2/1
50 / 100 / 150 yds
1d6
1d6
Fast
Long Bow
2/1
70 / 140 / 210 yds
1d6
1d6
Long range
Composite Short Bow
2/1
60 / 120 / 180 yds
1d6
1d6
Mounted cultures
Composite Long Bow
2/1
90 / 180 / 270 yds
1d6
1d6
Excellent range
Light Crossbow
1/1
60 / 120 / 180 yds
1d4+1
1d4+1
Simple
Heavy Crossbow
1/2
80 / 160 / 240 yds
1d4+1
1d6+1
Slow, strong
Sling Stone
1/1
40 / 80 / 160 yds
1d4
1d4
Common ammo
Sling Bullet
1/1
50 / 100 / 200 yds
1d4+1
1d6+1
Better ammo
Dart
3/1
10 / 20 / 40 yds
1d3
1d2
Very fast
Javelin
1/1
20 / 40 / 80 yds
1d6
1d6
Thrown
Simple range default: short +0, medium -2, long -5.
Thief Skills
Skill
Use
Pick Pockets
Steal or plant small items
Open Locks
Locks, manacles, mechanisms
Find/Remove Traps
Mechanical traps
Move Silently
Silent movement
Hide in Shadows
Concealment when conditions allow
Detect Noise
Listening carefully
Climb Walls
Sheer or difficult surfaces
Read Languages
Decipher unfamiliar writing
Roll d100 equal/under skill. Apply armour, race, Dex, tools, and situation as normal for thief skills. These are separate from the Xd6 ability-check system.
Moving faster than safe speed in darkness/ice: use a DEX ability check only if falling would be meaningful.
Overland Travel
Terrain
Movement Cost per Mile
Clear / farmland
1/2
Untravelled plains / grassland / heath
1
Barren / wasteland / rocky desert
2
Sand desert
3
Light forest
2
Medium forest
3
Heavy forest
4
Rolling hills
2
Steep hills / foothills
4
Low mountains
4
Medium mountains
6
High mountains
8
Medium jungle
6
Heavy jungle
8
Marsh / swamp
8
Tundra
3
Moor
4
Daily movement points ≈ movement rate × 2. Spend points by terrain cost per mile.
Example: Move 12 = 24 points/day. Heavy forest costs 4/mile, so about 6 miles/day.
Mounted Travel
Rule
Effect
Normal mounted travel
Miles/day roughly equals mount movement, adjusted by terrain
Main advantage
Mount carries gear and preserves rider endurance
Double movement
Mount saves vs death or becomes spent/lame
Triple movement
Save vs death at penalty; failure may kill mount
Horse care
Needs food, water, rest, and suitable terrain
Do not treat horses like motorbikes. Bad terrain, no water, and forced marches matter.
Light & Vision
Condition
Effect
Bright light
Normal sight
Torch / lantern
Visible from afar; attracts attention
Dim light
Search/attack penalties possible
Darkness
Cannot target normally without special sense
Infravision
Heat-based sight; may be spoiled by light/heat
Track torch/lantern duration.
Ask who carries the light.
Remember light reveals the party.
Rest & Healing
Condition
Healing
Normal rest
1 HP per day of low activity
Complete bed rest
3 HP per full day
Full week bed rest
21 HP + applicable Con HP bonus
No food/water/sleep
No natural healing that day
Magical healing
Immediate; cannot exceed max HP
Healing/herbalism proficiency
Minor benefits if used
Core death rule: at 0 HP, the character is dead unless using optional death’s door.
Death & Injury
Event
Rule
0 HP
Dead by core rule
Optional death’s door
0 to -10 dying state
50+ damage from one attack
Save vs death or die
Poison death
Poison may remain active after resurrection
Raise dead / resurrection
Use spell/item rules and resurrection survival
Optional Death’s Door
HP
State
0
Unconscious, helpless
-1 to -9
Dying; lose 1 HP/round until stabilised
-10
Dead
Stabilised
No further loss, cannot act
Use for dangerous-but-not-instantly-lethal campaigns.
Poison
Issue
Ruling
Poison save
Usually save vs poison; failure applies listed poison effect
Cure spells
Do not automatically neutralize poison
Neutralize poison
Stops poison; does not restore HP already lost
Debilitating poison
May prevent normal/magical healing until neutralized or elapsed
Poison after death
Venom can remain active for resurrection complications
Exploration Turns
Task
Handling
Search room
Costs time; roll if hidden thing matters
Listen at door
Quiet required; wandering risk
Force door
STR ability check if genuinely uncertain; noisy
Pick lock
Thief skill, or ability check only for improvised/non-thief rulings
Find/remove trap
Thief skill or careful description
Map
Needs light, pace, attention
Time passes.
Light burns.
Noise attracts.
Spells expire.
Wandering monsters may appear.
Doors, Traps, Secrets
Doors
Unlocked: opens unless stuck, barred, swollen, or held.
Stuck: STR ability check if uncertain; noisy.
Locked: key, thief skill, magic, force, or tools.
Traps
Foreshadow danger where fair.
Ask exactly how they inspect.
Reward smart precautions.
Roll only when uncertainty remains.
Trigger: attack, save, or automatic effect.
Secret Doors
Use racial chances, search time, magic, or description-led discovery.
NPCs
Want: what do they need?
Fear: what makes them back down?
Leverage: what can PCs offer?
Line: what will they not do?
Attitude
Meaning
Hostile
Hurts, blocks, betrays
Unfriendly
Refuses unless pressured
Neutral
Needs reason/payment
Friendly
Helps if not costly
Loyal
Takes risk for PCs
Treasure & XP
Treasure
Coins: common reward.
Gems/jewellery: portable wealth.
Magic items: wonder and power.
Maps/clues: future adventure.
Favours/titles/land/allies: campaign rewards.
XP Sources
Completing goals.
Overcoming monsters/hazards.
Recovering treasure if using that rule.
Class-specific achievements.
Good survival/problem-solving.
Wilderness
Set weather and terrain.
Choose pace and marching order.
Check navigation/lost if relevant.
Check encounters by region/time.
Track food, water, mounts, fatigue.
Camp: watches, healing, memorisation.
Hazard
Check
Exposure
CON ability check; survival proficiency shifts difficulty easier
Lost
WIS ability check; navigation proficiency shifts difficulty easier
Forced march
CON ability check
Foraging
WIS ability check; survival proficiency shifts difficulty easier
Ambush
Surprise / scouting
Common Rulings
Help
Help should change the fictional situation, not add a bonus. If a helper meaningfully improves the method, set a lower base difficulty before the roll. If the help removes uncertainty, do not roll.
Group Checks
Use the best character if one lead makes sense. Use majority success if everyone must manage individually. Apply proficiency shifts individually if the characters have different training.
Retrying
Allow a retry only if time, tools, method, or circumstances change. Otherwise failure stands.
Fail Forward
Failure causes cost, delay, danger, noise, damage, lost resource, worse position, or hard choice.
Fast Combat Math
Task
Formula
Example
Hit number
THAC0 − AC
THAC0 17 vs AC 4 = need 13+
Apply attack bonus
Needed number − bonus
Need 13, +2 sword = need 11+
Apply attack penalty
Needed number + penalty
Need 13, -2 darkness = need 15+
Convert AC
Ascending AC = 20 − AD&D AC
AD&D AC 3 = Asc AC 17
Ability check
Roll Xd6 ≤ ability score
DEX 15, Hard = roll 4d6; success on 15 or less
How To Run Common Scenes
Combat
Draw positions or describe range.
Ask declarations.
Roll initiative.
Resolve actions.
For attacks: THAC0 − AC, roll d20, roll damage.
Call saves where required.
Check morale after a major setback.
Search
Ask where and how they search.
Spend time.
If method reveals it, reveal it.
If uncertain, roll appropriate check.
Failure costs time, noise, danger, or missed clue.
Social
Decide NPC desire and fear.
Let players speak or summarise approach.
Judge leverage, threats, reputation, and what is being asked.
Roll only if outcome is uncertain and failure matters.
Partial success: help with price, delay, condition, or risk.
Encounter Design
Good Encounter Checklist
Clear situation.
Interesting terrain.
Monster/NPC goal.
At least one non-combat option.
Reward or clue.
Consequence if ignored.
Pressure Tools
Pressure
Use
Time
Ritual completes, guards arrive
Noise
Wandering monsters
Light
Torches run out
Supplies
Food, water, arrows
Morality
Hostages, innocents, oaths
Session Opening Checklist
1 Recap last session.
2 State current danger/opportunity.
3 Confirm marching order or positions.
4 Confirm light sources.
5 Confirm active spells/effects.
6 Ask: “What do you do?”
Source / Table Notes
This screen is designed as a fast play aid, not a replacement for the books. Armour values, THAC0 table, healing, death, movement, and equipment summaries follow AD&D 2e core references. The Xd6 roll-under ability-check system, nonweapon proficiency shifts, AC ascending converter, and fail-forward advice are table tools added for speed and consistency.