Core d20 Mechanic

d20 + Ability Modifier + Proficiency Bonus (if proficient) ≥ DC

Roll a d20, add your ability modifier, and add your proficiency bonus if you're trained. Meet or beat the Difficulty Class (DC) to succeed. This same formula covers ability checks, attack rolls, and saving throws (saves).

Proficiency Bonus by Level

Levels	Bonus	Levels	Bonus	Levels	Bonus
1–4	+2	9–12	+4	17–20	+6
5–8	+3	13–16	+5

Common DCs

DC	Difficulty	DC	Difficulty
5	Very Easy	20	Very Hard
10	Easy	25	Extremely Hard
15	Medium	30	Near Impossible

Ability Modifier Formula

Modifier = (Score − 10) ÷ 2, rounded down. Score 10–11 = +0. Every 2 points above 10 adds +1: score 12–13 → +1, 14–15 → +2, 16–17 → +3, 18–19 → +4, 20 → +5.

Advantage & Disadvantage

Advantage: Roll the d20 twice — take the higher result.
Disadvantage: Roll the d20 twice — take the lower result.
Multiple sources of Advantage/Disadvantage never stack — one of each cancels out (roll normally).
Passive Score: When no roll is made (e.g. passive Perception), score = 10 + modifier + PB (if proficient).

Ability Scores

STR

Strength

Melee attacks, Athletics, carrying, breaking things.

DEX

Dexterity

Finesse/ranged attacks, AC, Acrobatics, Stealth, Sleight of Hand.

CON

Constitution

Hit points, concentration saves, endurance.

INT

Intelligence

Arcana, History, Investigation, Nature, Religion. Wizard casting.

WIS

Wisdom

Perception, Insight, Medicine, Animal Handling, Survival. Cleric/Druid/Ranger casting.

CHA

Charisma

Deception, Intimidation, Performance, Persuasion. Bard/Paladin/Sorcerer/Warlock casting.

Skills by Ability

STR

Athletics

DEX

Acrobatics, Sleight of Hand, Stealth

INT

Arcana, History, Investigation, Nature, Religion

WIS

Animal Handling, Insight, Medicine, Perception, Survival

CHA

Deception, Intimidation, Performance, Persuasion

Your Turn in Combat

Move Up to your Speed (30 ft. default). Can be split before and after your Action.

Action Attack, Cast a Spell, Dash, Disengage, Dodge, Help, Hide, Ready, Search, Use an Object…

Bonus Action Only when a class feature, spell, or ability specifically grants one.

Reaction Once per round, on your turn or another's. Recharges at the start of your next turn.

Initiative

Roll a d20 + DEX modifier — highest goes first.
Surprise: Surprised creatures skip their first turn (no Actions, Bonus Actions, Reactions, or movement).
Opportunity Attack: Reaction. Triggered when a hostile creature you can see leaves your melee reach without using Disengage.

Movement Rules

Difficult terrain costs 2 ft. of movement per 1 ft. traveled.
Standing from prone costs half your Speed.
Climbing and swimming each cost 2 ft. per 1 ft. (unless you have that specific speed).

Common Actions in Combat

Action

Attack

Make one melee or ranged weapon attack (or more with Multiattack). Includes unarmed strikes (1 + STR mod bludgeoning damage).

Action

Cast a Spell

Cast a spell with a casting time of 1 Action. Spells with Bonus Action or Reaction casting times use those instead.

Action

Dash

Gain extra movement equal to your Speed this turn (total = double Speed).

Action

Disengage

Your movement doesn't provoke Opportunity Attacks for the rest of the turn.

Action

Dodge

Until your next turn: attack rolls against you (from creatures you can see) have Disadvantage, and you have Advantage on DEX saves.

Action

Help

Grant an ally Advantage on their next ability check — or their next attack roll against a creature within 5 ft. of you.

Action

Hide

Make a DEX (Stealth) check. On success you're hidden while you remain out of sight and hearing.

Action

Ready

Declare a trigger and an action. Use your Reaction to act when the trigger occurs (before your next turn).

Action

Search

Make a WIS (Perception) or INT (Investigation) check to find something hidden or deduce information.

Action

Grapple / Shove

Special melee attacks using STR (Athletics). Grapple: contest vs. STR (Athletics) or DEX (Acrobatics) — success = target is Grappled. Shove: same contest — success = push 5 ft. or knock Prone.

Reaction

Opportunity Attack

When a hostile creature you can see leaves your melee reach without Disengaging, make one melee weapon attack.

Luck

Every PC has a Luck resource (0–5). Use it to influence any check.

1

2

3

4

5

Gaining Luck

Once per turn, when you fail an attack roll or fail a save, gain 1 Luck.
The GM may award 1 Luck for clever ideas, excellent roleplaying, or interesting (rather than optimal) choices.
The GM may award any amount of Luck after surviving difficult encounters or achieving story goals.

Luck Cap

Maximum is 5 Luck. If you would gain Luck at 5, roll a d4 and reset your Luck to that number. Spend it before you lose it!

Spending Luck

Spend any amount of Luck to add +1 per Luck to any check you make.
Spend 3 Luck to reroll a d20 immediately after making any check (attack, ability check, or save).
Luck can't turn a natural 1 into a hit or push a result to 20 to trigger a critical hit.
Luck gained from a failed roll cannot be spent to affect that same roll.

Attack Rolls & Damage

Attack Roll

d20 + Ability Mod + PB ≥ Target AC

Melee: STR modifier (or DEX if Finesse property).
Ranged: DEX modifier. Disadvantage if within 5 ft. of a hostile creature.
Natural 1 (on the die): Critical miss — automatic miss.
Natural 20 (on the die): Critical hit — automatic hit!

Critical Hit

Roll all of the attack's damage dice twice, then add modifiers once.
Example: a longsword normally deals 1d8+3. A crit deals 2d8+3.

Armour Class (AC)

Armour Type	AC Formula
Unarmoured	10 + DEX mod
Light Armour	Base AC + DEX mod
Medium Armour	Base AC + DEX mod (max +2)
Heavy Armour	Fixed AC (no DEX mod)
Shield	+2 AC (one free hand required)

Cover

Half Cover: +2 bonus to AC and DEX saves.
Three-quarters Cover: +5 bonus to AC and DEX saves.
Total Cover: Cannot be targeted directly.

Hit Points & Death Saves

HP at 1st level: Max hit die + CON modifier.
HP per level: Roll hit die + CON modifier.
At 0 HP: Fall Unconscious (Dying). Make Death Saves.
Instant death: Damage remaining after reaching 0 HP equals or exceeds your HP maximum.

Death Saving Throws

At the start of each turn at 0 HP, roll a d20 (no modifiers).

Success

3 = stable

Failure

3 = dead

Roll 10+ = success. Below 10 = failure.
Natural 20: Regain 1 HP.
Natural 1: Two failures.
Any damage at 0 HP = 1 failure (crit = 2).
Any healing stabilizes and restores HP.
A stable creature regains 1 HP after 1d4 hours.

Resting

Short Rest

1 hour of light activity. Spend Hit Dice to recover HP: roll each die + CON modifier.

Spend as many Hit Dice as you wish (up to your total).
Half your expended Hit Dice are recovered on a Long Rest.

Long Rest

8 hours (max 2 hrs light activity). Requires at least 1 HP. Once per 24 hours.

Regain all lost HP.
Regain half your total Hit Dice (min 1).
Regain all spell slots.
Most class features recharge.

Spellcasting Basics

Spell Save DC 8 + PB + Spell Mod

Spell Attack Bonus PB + Spell Mod

Spell Circles & Slots

Spells have a Circle (cantrip or 1st–9th). Use a slot of at least that circle to cast it.
Casting with a higher circle slot than required often enhances the spell (At Higher Circles).
Cantrips use no slots — cast them freely.
All spell slots recharge on a Long Rest.

Magic Sources

Arcane

Bard, Mechanist, Sorcerer, Warlock, Wizard. Powered by study or innate talent.

Divine

Cleric, Paladin. Granted by deities or sacred oaths.

Primordial

Druid, Ranger. Drawn from natural forces and the living world.

Wyrd

Warlock, Sorcerer (some). Power from fate, dark pacts, or the uncanny.

Components

V (Verbal): Must be able to speak. Silenced casters cannot cast V spells.
S (Somatic): Requires a free hand for gestures.
M (Material): Requires the component or a spellcasting focus to substitute.

Concentration

Only one concentration spell at a time. Starting another ends the first.
When you take damage: CON save DC = max(10, half damage taken). Fail → spell ends.
Rituals: Cast without a spell slot by adding 10 minutes to the casting time — requires the Ritual Caster feature or the spell being known as a ritual.

Conditions

Blinded

Can't see. Auto-fails sight-based checks. Attacks against: Advantage. Own attacks: Disadvantage.

Charmed

Can't attack the charmer or target them with harmful effects. Charmer has Advantage on social checks vs. you.

Deafened

Can't hear. Auto-fails hearing-based checks.

Exhaustion

Six levels of mounting severity. Each level adds penalties. Level 6 = dead. One level removed per Long Rest.

Frightened

Disadvantage on ability checks and attacks while source is visible. Can't move closer to the source.

Grappled

Speed = 0. Ends if grappler becomes Incapacitated or you're moved out of reach.

Incapacitated

Can't take Actions or Reactions.

Invisible

Can't be seen without special sense. Attacks against: Disadvantage. Own attacks: Advantage.

Paralyzed

Incapacitated. Can't move or speak. Auto-fails STR/DEX saves. Attacks: Advantage. Hits within 5 ft. are crits.

Petrified

Turned to stone: Incapacitated, can't move, Resistance to all damage. Immune to poison and disease.

Poisoned

Disadvantage on attack rolls and ability checks.

Prone

Must crawl (costs half Speed to stand). Melee attacks against: Advantage. Ranged attacks against: Disadvantage.

Restrained

Speed = 0. Attacks against: Advantage. Own attacks and DEX saves: Disadvantage.

Stunned

Incapacitated. Can't move. Can speak only haltingly. Auto-fails STR/DEX saves. Attacks against: Advantage.

Surprised

On first turn: no Actions, Bonus Actions, Reactions, or movement. Determined before initiative is rolled.

Unconscious

Incapacitated. Can't move or speak, unaware of surroundings. Auto-fails STR/DEX saves. Hits within 5 ft. are crits.

How Tales of the Valiant Differs from D&D 5e

ToV is fully compatible with 5e content, but uses its own terminology and a few unique mechanics. Here are the key differences.

Lineage (not Race)

What 5e calls "Race" is called Lineage in ToV. Lineages include Beastkin, Dwarf, Elf, Human, Kobold, Orc, Syderean, and Smallfolk, plus others. Each Lineage has a suite of traits and features.

Heritage (not Subrace)

What 5e calls "Subrace" is called Heritage in ToV. Each Lineage has Heritage options that further define your character's traits. ToV's character sheet uses Heritage where 5e sheets show Alignment.

Talents (not Feats)

ToV uses Talents instead of Feats. They work the same way — granted at certain levels or through Ability Score Improvement choices — but are organised into Magic Talents, Martial Talents, and Technical Talents.

Spell Circles (not Spell Levels)

Spell power is measured in Circles (1st–9th) rather than Levels. The numbers are identical — a 3rd-circle spell costs the same as a 3rd-level slot. The phrase "At Higher Circles" replaces "At Higher Levels."

Four Magic Sources

Spells belong to one of four Sources: Arcane (Bard, Wizard, Sorcerer), Divine (Cleric, Paladin), Primordial (Druid, Ranger), and Wyrd (Warlock, some Sorcerers). Some spells appear on multiple Source lists.

Luck Resource

ToV adds a Luck resource (0–5) earned through failed rolls or GM rewards. Spend 1 Luck = +1 to any check; spend 3 Luck = reroll a d20. This is entirely absent from core 5e (it's not the Lucky feat).

The Mechanist Class

ToV's unique class is the Mechanist — a tinkerer who builds and deploys mechanical constructs. It occupies a similar design space to the 5e Artificer but is entirely original to ToV.

Classes & Compatibility

ToV includes: Barbarian, Bard, Cleric, Druid, Fighter, Mechanist, Monk, Paladin, Ranger, Rogue, Sorcerer, Warlock, Wizard. Most 5e subclasses, monsters, and adventures work without modification.