Rules for Using the Ability Scores in Old School Games

Designer's Notes

Original (Brown Box) D&D famously does not include detailed rules or suggestions for using the ability scores. Evidently, they were used for ability checks in the original campaigns (Arneson's Blackmoor, Gygax's Greyhawk, and Rob Kuntz's Kalibruhn); Kuntz in particular has noted that he called for ability checks using 3d6, 4d6, or 5d6 (based on difficulty) vs. the ability score. The following rules are inspired by 5e (see the SRD, pp. 76 ff.) and also by Daniel Collins' Original Edition Delta. 

They articulate with rules for character backgrounds and sub-classes that provide bonuses to relevant ability rules; these can be ignored or introduced at the referee's discretion. In my campaign I like to keep character background knowledge flexible; rather than only relying on a fixed skill list, characters gain a skill bonus to ability rolls if it seems like the roll in question relates to their background, class, or sub-class. For example, a ranger would gain a skill bonus on track rolls, but so would a character with the forester or nomad backgrounds.

Rules for Ability Scores

1. Starting Ability Scores

The player generates ability scores for his character using one of the following two methods (his choice). The first is to roll three six-sided dice once for each ability and assign the rolls as desired. The second is to assign the following scores to the abilities as desired: 6, 8, 10, 12, 14, and 16.

2. Ability Statistics

Ability Statistics Table

#	Ability	Abbr.	Prime Requisite	Adjustments	Other Uses
1	Charisma	Ch	n/a	Loyalty of retainers Reaction rolls	Number of retainers
2	Constitution	C	n/a	Hit die rolls Save vs. death ray or poison	n/a
3	Dexterity	D	Thief	Armor class Ranged attacks Save vs. dragon breath Save vs. wands	Order of action
4	Intelligence	I	Magic-user	Detect secret doors	Number of languages
5	Strength	S	Fighter	Melee attacks Melee damage Open doors	Encumbrance
6	Wisdom	W	Cleric	Save vs. staves and spells Save vs. turn to stone	n/a

Prime Requisite: Every adventuring class has one ability as its prime requisite. A character’s score in his prime requisite modifies the number of experience points (XP) earned on an adventure.

Prime Requisite Table

Ability Score	XP Modifier
0	*
1-6	-20%
7-8	-10%
9-12	0
13-14	+5%
15+	+10%

Ability Adjustments: An ability adjustment is added to relevant rolls and stats (see Ability Statistics Table).

Ability Adjustment by Ability Score Table

Ability Score	Ability Adjustment
0	*
1-4	-2
5-8	-1
9-12	0
13-16	+1
17-20	+2
21-24	+3
25	+4

*A character with an ability score of 0 is unable to use the ability for any action.

3. Ability Rolls

Ability rolls are used to determine the success of miscellaneous actions not covered by other rules. To test a character’s use of an ability, roll a 20-sided die and add the character’s ability score. The roll is successful just in case the total is 20 or higher.

Every ability has a list of standard actions associated with it. For example, charisma is associated with bargain, beg, bluff, courtesy, disguise, oratory, sing, and train animal rolls. Any character can attempt actions of the relevant kind by making an ability roll.

Some types of ability rolls can only be made by characters with a relevant skill or power. For example, a thief can use dexterity to cut purses or remove traps.

Skill Bonus: Characters who are especially skilled in the relevant kind of action—based on their class, sub-class, background, or in the judgment of the referee—receive a skill bonus to the ability roll equal to their experience level. For example, a noble receives a skill bonus to courtesy rolls.

Difficulty Level: A difficulty level is subtracted from an ability roll. The referee determines the difficulty level; the default is 0.

Difficulty Level Table

DL	Description
0	Normal
4	Heroic
8	Super-heroic
12	Legendary

4. Ability Descriptions

4.01 Charisma

Charisma measures a character’s force of personality, social intelligence, and leadership ability.

Loyalty of Retainers: The referee secretly determines the loyalty of a character’s hirelings and retainers by rolling three six-sided dice and adding his charisma adjustment. Loyalty modifies morale rolls during combat and other situations providing temptations or tests of resolve.

Number of Retainers: The maximum number of retainers a character can have is equal to his charisma score divided by two.

Reaction Rolls: A character’s charisma adjustment is added to a referee’s rolls to determine the morale or reactions of monsters or NPCs to the character.

Charisma Rolls Table

#	Charisma Roll
1	Bargain
2	Beg
3	Bluff
4	Courtesy
5	Disguise
6	Oratory
7	Sing
8	Train Animal

Bargain: The character can buy items at 20% less than the standard price or sell items for 20% more than the standard price.

Beg: The character can earn 1-6 pence (in coin or in kind) by spending 1-6 hours begging in a settled area.

Bluff: The character can temporarily distract or deceive others.

Courtesy: The character is familiar with the many unwritten rules and customs surrounding the nobility.

Disguise: The character can create convincing disguises, and adopt appropriate mannerisms and speech patterns.

Oratory: The character can sway the mood or change the beliefs of a group of listeners.

Sing: The character can entertain, inspire, or distract an audience through song.

Train Animal: The character can train a domesticated animal to perform mundane tasks or simple tricks. It takes at least one week to train an animal to perform one task.

4.02 Constitution

Constitution measures a character’s health and resistance to disease, fatigue, and injury.

Hit Die Rolls: A character’s constitution adjustment is added to all hit die rolls. A character receives one hit die per experience level; the size of hit die depends on the character’s adventuring class.

Save vs. Death Ray or Poison: A character’s constitution adjustment is added to saving throws to avoid the effects of a death spell, disease, or poison.

Constitution Rolls Table

#	Constitution Roll
1	Forced March
2	Hold Breath
3	Resist Hunger and Thirst
4	Resist Sleep

Forced March: The character can increase his daily movement rate by up to 50% without suffering ill effect. A failed roll imposes a -1 fatigue penalty to all rolls. Additional failed rolls increase the fatigue penalty by -1 each. One day of rest removes a fatigue penalty.

Hold Breath: The character can hold his breath for one minute without ill effect. A failed roll indicates the character loses 1 point of constitution, and continues losing 1 constitution per minute until he is able to breathe. The character dies when constitution reaches 0. Constitution lost through drowning returns after 1 minute of breathing.

Resist Hunger and Thirst: A character can go without water for two days or without food for four days without penalty (assuming temperate climate and a high level of activity). Thereafter the character must make a successful constitution roll or suffer a -1 fatigue penalty to all rolls and lose 1-6 points of constitution. The roll is repeated every two days (water) or every four days (food). Fatigue penalties are cumulative, and 0 constitution indicates death. Fatigue penalties are removed and lost constitution is restored after one day of adequate food and water.

Resist Sleep: A character can go without sleep for 48 hours without penalty. Thereafter the character must make a successful constitution roll or suffer a -1 fatigue penalty to all rolls. The roll is repeated every for every day without sleep and the fatigue penalties are cumulative. Fatigue penalties are removed after one day of rest.

4.03 Dexterity

Dexterity measures a character’s agility, balance, hand-eye coordination, and reaction time.

Armor Class: A character’s dexterity adjustment is subtracted from his armor class.

Order of Action: A character’s dexterity score can affect the order of action in a combat round at the referee’s discretion.

Ranged Attacks: A character’s dexterity adjustment is added to attack rolls made with ranged weapons, such as bows and thrown daggers.

Save vs. Dragon Breath: A character’s dexterity adjustment is added to saving throws vs. dragon breath or other area attacks that can be dodged.

Save vs. Wands: A character’s dexterity adjustment is added to saving throws vs. wands or other ray attacks that can be dodged.

Dexterity Rolls Table

#	Dexterity Roll
1	Balance
2	Build or Repair
3	Climb
4	Drive Vehicle
5	Escape Bonds
6	Pilot Vessel
7	Play Instrument
8	Ride

Balance: The character keeps his footing when on a ledge or precipice or in another situation requiring a stable posture.

Build or Repair: The character can create or repair a simple item relevant to his background, class, or sub-class (if any). The cost to build an item is generally half the retail value.

Climb: The character can climb vertical surfaces if there are sufficient handholds. A failed roll indicates a fall only if the roll is an unmodified ‘1’. The height at which a fall occurs is 10%-100% of the total height to be climbed (determine randomly). A character’s movement rate while climbing depends on the difficulty level.

Climb Difficulty Level Table

DL	Description	Movement Rate
0	Plentiful handholds, dry surface, stable surface, vertical surface	1/3
4	Any one: few handholds; slick surface; unstable surface; convex surface	1/6
8	Any two: few handholds; slick surface; unstable surface; convex surface	1/9
12	Any three: few handholds; slick surface; unstable surface; convex surface	1/12
16	Few handholds; slick surface; unstable surface; convex surface	1/24

Drive Vehicle: The character can handle animal-drawn vehicles in difficult conditions and perform special maneuvers, such as tight turns or bouncing over obstacles.

Escape Bonds: The character can break, cut, wiggle out of, or otherwise defeat ties, manacles, chains, or other bonds. The difficulty level is generally 4 or more (referee’s discretion).

Pilot Vessel: The character can handle small rowed or sailed vessels under difficult conditions.

Play Instrument: The character can play a musical instrument relevant to his background, class, or sub-class (if any).

Ride: The character can handle a mount under difficult conditions or perform a jump or other maneuver.

4.04 Intelligence

Intelligence measures a character’s knowledge, memory, and reasoning ability.

Detect Secret Doors: A character’s intelligence adjustment is added to his chance to detect secret doors and other hidden objects or creatures (base 1 in 6 chance).

Number of Languages: Every character knows at least two languages. One of a player character’s languages must be Valish, the Common Tongue of the Twilight Empire. The other is either the language of his homeland (if other than Valish), or one other human or nonhuman language of the player’s choice. Characters can learn one additional language per point of intelligence above 10. New languages can also be learned after the character has started adventuring. It takes at least one month of game time to learn a new language. If a character is busy adventuring, the time is longer—three months or more (referee’s discretion).

Native Languages by Homeland Table

#	Homeland	Alternate Name	Native Language	Old Earth Analogue*
1	Burath	Forest Peoples	Burathish	Welsh
2	Carpu	Scarp Mountains	Carpish	Romanian
3	Don	Green Isle	Donish	Gaelic
4	Dul	Lunar Empire	Dulish	Old Church Slavonic
5	Hur	Land of Trolls	Hurish	Russian
6	Hux	Sea Peoples	Huxish	Old Norse
7	Let	Eastern Marches	Letish	Prussian
8	Tur	Land of Towers	Turish	Rhaeto-Romansch
9	Val	Twilight Empire	Valish	Middle English
10	Ys	Ice Isle	Huxish	Old Norse
11	Zargoz	Western Marches	Zargozish	Galician
12	Zun	Snow Peoples	Zunish	Sami

*Historical human languages are used as analogues for the “actual” human languages in Telleth-Rumi.

Ancient Human Languages Table

#	Language	Currently Used By	Originally Used By	Analogue
1	Demotic	Clerics and magic-users	Pantarchy—commoners	Latin
2	Hieratic	Clerics and magic-users	Pantarchy—scholars	Greek
3	Old Terran	Magic-users and sages	Galactic Empire	Indo-European
4	Old Valish	Magic-users and sages	Ancient Val	Old English

A player character may learn a nonhuman language with the referee’s permission. Generally, such languages are only known by magic-users, cultists, druids, sages, or people who have allied with or dwelt among nonhumans (such as a person kidnapped and raised by faeries).

Nonhuman Languages Table

#	Language	Native Speakers
1	Abyssal	Elder gods and beasts of chaos
2	Celestial	Celestial spirits
3	Draconic	Dragons
4	Elemental	Elemental spirits (gnomes, salamanders, sylphs, undines, etc.)
5	Elfish	Seelie faeries (brownies, dwarves, elves, nixies, pixies, etc.)
6	Gigantic	Giants
7	Infernal	Infernal spirits
8	Trollish	Unseelie faeries (goblins, trolls, hobgoblins, bugbears, etc.)

Intelligence Rolls Table

#	Intelligence Roll
1	Appraise
2	First Aid
3	Folk Lore
4	Gaming
5	Natural Lore
6	Scribe

Appraise: The character can determine the approximate retail value of a natural commodity or manufactured item.

First Aid: The character can stabilize a dying character. First aid must be performed within 1 hour of the infliction of a wound or injury.

Folk Lore: The character can recall information from folk tales, history, legends, and other commonly known (or widely believed) bits of lore.

Gaming: The character can win a game of skill, such as a card, dice, or board game, as long as the outcome is not based purely on chance.

Natural Lore: The character can identify plants, animals, minerals, or other natural phenomena in familiar terrain (if any).

Scribe: The character can read and write, create an accurate copy of a written work, or compose an original written document such as a contract, journal, ledger, or proclamation.

4.05 Strength

Strength measures a character’s muscle power and stamina.

Encumbrance: A character can carry up to 10 times his strength in pounds without penalty. Carrying more than this limit encumbers a character: reduce movement rate by one-third, and other penalties at the referee’s discretion. Base movement rate is 12 scale inches per turn. Carrying more than 20 times strength in pounds reduces the movement rate by two-thirds and imposes a -4 penalty on rolls for actions requiring physical activity. The maximum a character can lift is 30 times strength in pounds, which permits only 1” movement per turn.

Melee Attacks: A character’s strength adjustment is added to attack rolls for melee attacks.

Melee Damage: A character’s strength adjustment is added to damage rolls for melee attacks.

Open Doors: A character’s strength adjustment affects rolls to open stuck or held doors (base 2 in 6 chance).

Strength Rolls Table

#	Strength Roll
1	Jump
2	Swim

Jump: The character can perform a running vertical jump up to half his movement rate, a standing horizontal jump up to half his movement rate, or a running horizontal jump equal to one and a half times his movement rate.

Swim: The character is able to stay afloat in difficult conditions or if weighed down by gear.

4.06 Wisdom

Wisdom represents a character’s insight, intuition, situational awareness, and willpower.

Save vs. Staves and Spells: A character’s wisdom adjustment is added to saving throws to avoid the effects of magical staves and spells.

Save vs. Turn to Stone: A character’s wisdom adjustment is added to saving throws to avoid magical effects which turn a character to stone or otherwise systematically transform the character’s person.

Wisdom Rolls Table

#	Wisdom Roll
1	Animal Husbandry
2	Direction Sense
3	Fish
4	Outdoor Survival
5	Track
6	Weather Sense

Animal Husbandry: The character can raise, care for, or assess the value of cattle, goats, horses, sheep, or other domesticated animals.

Direction Sense: The character can determine which way is north.

Fish: The character can catch a fish or other edible freshwater or saltwater creature with the right equipment (line, net, or spear).

Outdoor Survival: In familiar terrain (if any), the character can forage, find water, build a shelter, and start a fire, even under wet or otherwise difficult conditions. Characters raised in a town generally do not have a familiar terrain. This ability only transfers to unfamiliar terrain if the character has been trained by locals or others familiar with survival in the new terrain type.

Track: The character can follow a trail. The difficulty level increases on stony terrain (+4), after a rain (+4), if the quarry crosses a river (+4), or if the trail is old (+2 or more).

Weather Sense: The character can predict the weather up to 1 day in advance.