Contents ​

The supplement is organized in publication order, with quick-reference material at the end.

0. What Kind of Game Is This? ​

This game uses AD&D 2nd Edition as its foundation, with selected modern rules added where they make play clearer or smoother. It will feel familiar in some ways, but its underlying assumptions are different from those of 5th Edition.

5e uses bounded accuracy, keeping attack bonuses, Armor Class, and target numbers within a relatively narrow range. AD&D is comparatively unbounded: advancement and magic can create much wider gaps, so weak opponents may become nearly irrelevant while some powerful foes may be practically untouchable until the party gains levels, equipment, or a better plan.

In 5e, encounters are often designed as balanced contests. The party is expected to engage with them, spend an appropriate amount of resources, and usually win. AD&D is less concerned with making every encounter a fair fight. Encounters arise from the location, the creatures living there, random chance, and the ongoing situation. The world is not automatically adjusted to match the party's level.

You may encounter enemies that are too powerful to defeat in a direct fight. This is not necessarily a mistake or an indication that you have missed the intended solution. Sometimes the correct response is to avoid the threat, negotiate, create a diversion, barricade a passage, exploit the terrain, or run away. Escaping from a dangerous situation can itself be the challenge.

Combat is only one tool. Gathering information, scouting, planning routes, hiring assistance, preparing equipment, setting ambushes, controlling when and where a fight happens, and deciding when not to fight are often more important than the abilities written on the character sheet. Your character's statistics matter, but the game also expects you to rely heavily on your own judgment, caution, and creativity.

Enemies do not necessarily attack on sight or fight to the death. Reaction rolls, morale, competing interests, fear, greed, and self-preservation all matter. A group of hostile creatures may be bribed, intimidated, misled, divided, recruited, or convinced that fighting is not worth the risk. Likewise, an enemy that begins to lose may surrender or flee rather than remain in combat until reduced to zero hit points.

The game is more dangerous than 5e. Characters have fewer safety mechanisms, healing is less abundant, and poor decisions can have serious consequences. Death is not always permanent, but resurrection is difficult, uncertain, and limited. It requires access to powerful magic, may demand significant cost or obligation, requires a resurrection survival roll, and permanently reduces Constitution. Recovering and restoring a fallen character may become an adventure in itself.

This does not justify arbitrary lethality. Serious dangers should usually be telegraphed clearly enough for careful players to recognize when fighting is a bad idea. Rumors, tracks, corpses, damaged structures, frightened witnesses, unusual silence, and other clues can all indicate that something dangerous lies ahead.

Victory is therefore less automatic. Surviving a difficult expedition, defeating a dangerous enemy through careful planning, rescuing a fallen companion, or escaping from something that could have destroyed the party should feel like a genuine accomplishment.

Character advancement is also slower. You should not expect to gain a level every few sessions or receive a major new class ability at every level. A character's growth comes from more than class progression. Magic items, scrolls, potions, wands, specialized equipment, allies, retainers, followers, property, reputation, political influence, secret knowledge, and access to powerful institutions can all change what the party is capable of doing.

These rewards are not merely substitutes for class features. They are part of the game's larger structure. A loyal retainer, a map to a forgotten entrance, a favor owed by a temple, or a wand with six charges may be more important than a numerical improvement on the character sheet. Characters become powerful partly by building relationships and accumulating resources in the world.

Magic requires more advance planning than it does in 5e. Wizards and priests prepare specific spells rather than choosing freely from all prepared magic at the moment of casting. A spellcaster who expects the wrong kind of danger may not have the ideal spell available. Information, prediction, and preparation therefore matter greatly.

Unlike 5e, AD&D does not impose a universal limit of one concentration spell at a time. Many ongoing spells can coexist, allowing careful players to layer compatible protections, enhancements, and battlefield effects. Individual spells may still require concentration or restrict other actions, and the same effect does not necessarily stack with itself, but spellcasters can generally maintain several compatible effects at once.

Spellcasters are expected to supplement memorized spells with scrolls, potions, wands, staves, and other magical resources. These items provide much of the flexibility that spontaneous casting supplies in later editions. Charges and consumable items are meant to be used, not preserved forever for an imaginary future emergency.

Resource management extends beyond spell slots. Light, ammunition, food, healing, time, carrying capacity, safe resting places, and the risk of additional encounters all influence decisions. Continuing deeper into danger may offer greater rewards, but retreating while the party still has the ability to do so is often the wiser choice.

The campaign is not intended to reject everything developed in later editions. We are adopting 5e rules where they improve clarity, reduce unnecessary bookkeeping, or make tactical play easier without undermining AD&D's structure. The goal is not to reproduce every awkward rule from 1989. It is to preserve a style of play built around exploration, uncertainty, preparation, meaningful danger, and player-driven problem solving while using modern mechanics where they fit.

1. Design Goals and Scope ​

1.1 Change Map ​

2. Core Mathematical Conversion ​

2.1 Ascending Armor Class ​

2.2 Attack Bonuses ​

Example: A character with THAC0 16 has a +4 attack bonus. An opponent with descending AC 2 has ascending AC 18. The character still needs a natural 14: 14 + 4 = 18.

Natural rolls: A natural 20 always hits and a natural 1 always misses. A natural 1 has no additional fumble effect. See Section 12.1 for critical hits.

Dual notation: During transition, stat blocks may show both values, such as AC 18 [2] and Attack +4 [THAC0 16].

3. Tactical Scale and Movement ​

3.1 Determining Movement Rate (MR) ​

MR is the Player’s Handbook movement statistic. Use the character’s current Movement Rate after racial base rate, encumbrance, magic, and other adjustments. AD&D monster statistics often abbreviate the same value as MR; treat a listed MR number as MR unless the entry states a special movement mode.

Base Movement Rates ​

For tactical play, the slower player-character races use MR 10 instead of their printed MR 6. This produces a 25-foot move while acting, rather than a 15-foot move.

Reading Other Movement Notation ​

Encumbrance ​

Use PHB Table 47 to determine the character’s encumbrance category from Strength and carried weight. Then apply the category below to the character’s house-rule base MR. Fractions are rounded down. The detailed PHB Table 48 method is not used with this tactical movement system because it assumes the printed base rates of 12 and 6.

Human example: A lightly encumbered human has current MR 8. The character can move 4 squares (20 feet) while attacking or 8 squares (40 feet) with a Full Move.

Dwarf example: An unencumbered dwarf has house-rule MR 10 and can move 5 squares (25 feet) while attacking. Under moderate encumbrance, the dwarf has current MR 5 and can move 2 squares (10 feet) while attacking or 5 squares (25 feet) with a Full Move.

3.2 Grid Scale ​

• One square represents 5 feet.
• A Medium or smaller creature normally occupies one square.
• One point of Movement Rate (MR) equals one square of full tactical movement.
• Diagonals cost one square. This favors speed and clarity over exact geometric measurement.
• Difficult terrain costs two squares for each square entered.
• Fractions are rounded down, to a minimum movement allowance of one square when movement is otherwise permitted.

3.3 Gridless Miniatures ​

• One inch of tabletop distance equals one 5-foot square and one point of Movement Rate.
• Measure the actual path taken by the miniature. Difficult terrain costs 2 inches of movement for each inch crossed.
• Normal 5-foot melee reach requires base contact. Each additional 5 feet of reach extends 1 inch beyond base contact.
• Ranges and areas are measured from the nearest point of the origin base. A miniature is affected by an area if any part of its base lies within the template.
• Large creatures use their actual base footprint. Miniatures cannot end movement with overlapping bases.

3.4 Movement Modes ​

3.5 Positioning ​

Split movement: A creature may divide permitted movement before, between, and after its attacks, provided it does not exceed the action’s movement allowance.

Facing: The core rules do not track facing. A creature threatens all squares within its reach.

Flanking: There is no default flanking bonus. Positioning already matters through reach, cover, blocked movement, and opportunity attacks.

Occupied squares: A creature cannot normally move through an enemy’s space. Movement through an ally’s space is permitted, but the ally’s square counts as difficult terrain and cannot be used as an ending space.

4. Turn Structure and Actions ​

4.1 Round Sequence ​

Resolve start-of-round effects and refresh each creature’s reaction.

Players who intend to cast spells declare those spells. Other actions are not declared.

Each side rolls initiative. Lower modified results act first.

On its turn, each creature chooses an action, uses any permitted movement, and resolves attacks or effects.

Resolve end-of-round durations, morale checks, and other campaign procedures.

4.2 Standard Actions ​

4.3 Multiple Attacks ​

Attack action: All attacks granted for the round belong to the same Attack action; extra attacks do not grant extra actions or extra movement allowances.

Three attacks every two rounds: A 3/2 attack progression continues to alternate between one attack and two attacks in successive rounds.

Rate of fire: A missile weapon’s rate of fire determines the number of shots made with the Attack action. Loading, ammunition, line of sight, and other 2e restrictions still apply.

Split movement: A creature may divide its permitted half movement among multiple attacks, allowing movement between attacks.

4.4 Brief Interactions ​

Free interaction: Once during a creature’s turn, it may perform one brief interaction incidental to its movement or action without spending its action. Drawing or switching a weapon may postpone the turn under Section 6.2.

4.5 Standing and Crawling ​

Standing: Standing from prone costs movement equal to half the creature’s current MR. A creature taking the Attack action can normally stand and attack but has no movement remaining.

Crawling: Each square or inch crawled costs 2 movement points. Because an ordinary action permits half MR, a prone creature normally crawls up to one-quarter MR while acting.

5. Reactions and Opportunity Attacks ​

Reaction limit: Each creature may take one reaction per round. The reaction refreshes at the beginning of the next round.

Opportunity attack trigger: A creature provokes when it voluntarily leaves an enemy’s reach without withdrawing.

Resolution: The enemy may spend its reaction to make one melee attack. This is a single attack, not the creature’s full attack routine.

Movement within reach: Moving from one threatened square to another without leaving the enemy’s reach does not provoke.

No trigger: Forced movement, teleportation, falling, and other movement not caused by the creature’s own movement do not provoke.

Withdraw: The Withdraw action prevents opportunity attacks caused by that movement.

Readied actions: Resolving a readied action consumes the same reaction that could otherwise be used for an opportunity attack.

6. Initiative and Spellcasting ​

6.1 Initiative Procedure ​

Combat uses the side-based initiative of the Player’s Handbook together with its optional individual modifiers: one d10 per side, with each combatant applying its own modifier to the side’s roll.

• Each side rolls 1d10 at the start of the round and applies the Player’s Handbook standard situational modifiers (haste and slow, higher ground, receiving a charge, poor footing, and the like). Compare each combatant’s modified total across sides; lower totals act first.
• Each combatant then applies its own entry from the full optional individual-modifier table: a declared spell adds its casting time; magic item activation, innate spell-like abilities, and breath weapons add their listed modifiers; anyone else adds the speed factor of the slowest ready weapon. Weapon speed and casting time never stack.
• A combatant with no ready weapon, or one using only unarmed or natural attacks, adds +0.
• Dexterity does not modify initiative, and this supplement adds no house initiative modifiers of its own.
• Tied modified totals resolve simultaneously.

Example: The party’s side rolls 4. A wizard who declared a spell with casting time 3 resolves it on 7, an ally with a long sword (speed factor 5) acts on 9, and an unarmed monk acts on 4.

6.2 Weapon Speed and Readiness ​

Weapon speed represents the readiness cost of the weapon already in hand. It modifies initiative without requiring a character to declare an attack.

Adjusted speed factor: Start with the weapon’s printed speed factor. Reduce it by the weapon’s magical attack bonus, to a minimum of 0. If a weapon has different magical bonuses against different targets, use the lesser bonus, as in the original 2e rule.

• At the start of the round, use the slowest weapon currently wielded and ready. A combatant with no ready weapon, or one using only unarmed or natural attacks, adds +0.
• When two weapons are wielded, use the weapon with the greater speed factor.
• Drawing or switching to a slower weapon before completing the substantive action recalculates initiative using that weapon. If the new count is later than the current count, postpone the remainder of the turn to the new count.
• Switching to a faster weapon never improves initiative during the current round. The combatant retains the slower initiative already established.
• A weapon drawn after the substantive action is complete does not retroactively delay that action, but it cannot be used for another normal attack that round. It is ready for reactions and the next round.
• Spellcasting uses casting time instead of weapon speed; the two modifiers do not stack.
• Weapon speed never delays reactions. A weapon must already be ready to make a weapon reaction unless a specific rule permits drawing it as part of the reaction.

6.3 Spell Interruption ​

Interruption window: A declared spell is vulnerable from the beginning of the round until it resolves at the caster’s modified initiative.

Damage: If the caster takes damage before the spell resolves, the spell is interrupted and lost.

Loss of components or attention: A condition that prevents required speech, gestures, material-component use, or deliberate spellcasting interrupts the spell.

No retroactive interruption: Damage taken after the spell resolves has no effect on that casting.

6.4 Sustained Effects ​

AD&D 2e has no universal 5e-style concentration rule. “Sustained” is a defined duration used only when an effect explicitly says so.

7. Surprise and Ambushes ​

7.1 Determine Awareness ​

Detection first: Resolve whether either side notices the other using the abilities and circumstances that actually apply: thief skills, ranger abilities, racial senses, relevant NWPs, a Wisdom check by an assigned lookout, illumination, noise, tracks, scent, concealment, terrain, and monster abilities.

Clear detection: A side that detects the threat with enough warning cannot be surprised by that threat.

7.2 Surprise Roll ​

Modifiers: Apply existing racial, class, monster, and situational surprise modifiers to the retained die. Advantage or disadvantage on the surprise roll does not stack with itself.

7.3 Effects of Surprise ​

• If both sides are surprised, the effects cancel and normal initiative begins.
• If only one side is surprised, resolve one surprise round before normal initiative.
• A surprised creature cannot move, act, or use reactions during the surprise round. It loses Dexterity bonuses to AC, and attacks against it gain +1.
• Ordinary surprise permits movement, melee attacks, missile attacks, and magical-item use by the unsurprised side, but not spellcasting.
• Surprise imposes no general saving-throw penalty unless a particular attack or effect says otherwise.

7.4 Prepared Ambushes ​

Ambush: A successfully concealed ambush causes the victims to make the disadvantage surprise roll. Ambushers may cast spells during the resulting surprise round because the timing and spell were prepared in advance. Do not make a second surprise roll afterward.

8. Cover, Conditions, and Spell Targeting ​

8.1 Cover ​

8.2 Standard Conditions ​

Specific overrides general: A spell or monster ability may add, remove, or replace parts of a standard condition. The glossary supplies the default meaning when the effect does not restate it.

8.3 Line of Sight and Unobstructed Paths ​

AD&D spell descriptions do not consistently use a single universal line-of-effect rule. Use the following default only when the spell text does not decide the question.

Examples: A magic missile or projected bolt cannot pass through a closed window. A direct enchantment such as charm or hold may target a clearly visible creature through ordinary glass unless the spell says otherwise. A touch spell still requires actual contact.

9. Advantage and Disadvantage ​

No stacking: Multiple sources of advantage do not add further dice. Multiple sources of disadvantage do not add further dice.

Cancellation: If both advantage and disadvantage apply, they cancel and the roll is made normally, regardless of how many sources exist on either side.

Keep numeric modifiers: Armor, cover, magic weapons, ability adjustments, range, specialization, and other stable measurable effects retain their normal numeric modifiers.

Use advantage for circumstances: Use it for surprise positioning, meaningful assistance, poor footing, impaired senses, especially favorable plans, and similar transient situations that would otherwise generate ad hoc modifiers.

10. Ability and Proficiency Checks ​

10.1 Untrained Proficiency Attempts ​

Characters may attempt plausible actions without the corresponding NWP, but training still controls advanced and reliable use.

Untrained check: For a trainable task, use the NWP’s listed ability and normal modifier, then apply an additional -4 penalty to the adjusted score. Roll low as usual.

Tools and circumstances: Required tools, materials, time, assistance, and familiarity still apply. Missing essential tools may impose another penalty or make the attempt impossible.

10.2 System Shock ​

System Shock is removed as a general character statistic and retained only through the game’s existing death saving throw when a specific effect explicitly requires a bodily-survival test.

Replacement rule: System Shock is not used as a general character statistic. Voluntary transformation, beneficial magic, magical aging, petrification reversal, and similar effects do not require an additional survival roll. When an individual spell or effect explicitly requires a System Shock check, make a saving throw versus death instead.

11. Races and Advancement ​

11.1 Human Versatility ​

At 1st level, a human character receives one additional nonweapon proficiency slot.

11.2 Racial Level Limits ​

Racial class level limits are soft limits. Demihumans may continue advancing beyond the applicable limit, but advancement above it requires twice the normal experience-point increment.

12. Weapons and Equipment Presentation ​

No silent rebalance: Adding a property label does not change a weapon’s damage, speed, rate of fire, cost, proficiency category, or specialization rules unless a specific house rule says otherwise.

Damage categories: Retain separate damage against Small/Medium and Large targets where the original weapon table provides it.

Specialization: Weapon specialization remains a fighter-class subsystem and is not replaced by a universal proficiency bonus.

12.1 Critical Hits ​

Critical hits use the simple 2e double-dice method, with a confirmation built into the original attack total rather than a second roll.

A natural 20 always hits. It is a critical hit only if the modified attack total would also equal or exceed the target’s Armor Class. If the natural 20 hits only because of the Rule of 20, it is a normal hit.

Eligible Attacks and Damage ​

Backstabs and Other Damage Multipliers ​

Critical backstab: Multiply the thief's normal backstab multiplier by ×2 for the critical hit. This multiplies only the weapon's base damage; add Strength, specialization, and magical weapon bonuses once afterward.

Other multipliers: When a critical hit combines with charge damage or another multiplier, add the multipliers rather than multiplying them together unless a specific rule says otherwise: combined multiplier = 1 + the sum of each multiplier minus 1.

Symmetry: The rule applies equally to player characters, NPCs, and monsters. Multiple attacks create multiple opportunities to score a critical hit; there is no one-critical-per-round limit.

12.2 Spell Critical Hits ​

Spell criticals use an attack roll or saving throw that the effect already requires. Never make a separate critical-check roll.

Only a spell or magical effect that directly inflicts hit-point damage can critically hit. Resolve magic resistance first; an effect that is completely resisted cannot critically hit.

Area Effects and Repeated Damage ​

• For an area spell, each target’s saving throw determines separately whether that target suffers a critical hit.
• The normal damage roll may be shared among all targets. Roll the additional critical-damage dice only for a target whose natural 1 also fails after modifiers.
• If an effect makes repeated attack rolls, each attack can critically hit normally.
• If an effect deals ongoing damage without another attack roll or saving throw, only its initial application can critically hit. Later automatic damage does not.

Examples ​

13. Wizard Spell Capacity and Cantrips ​

13.1 Bonus Spells from Intelligence ​

A wizard with Intelligence 13 or higher gains bonus wizard spell slots by using the PHB priest bonus-spell progression with Intelligence in place of Wisdom. The table below states the cumulative bonus slots directly.

• Bonus slots are cumulative and are added to the wizard’s normal daily spell allotment.
• A bonus slot of a given spell level is unavailable until the wizard can normally memorize spells of that level.
• Specialist bonus spells and Intelligence bonus spells stack.
• Intelligence bonus slots do not increase prepared-cantrip capacity.
• These bonuses apply to wizard-class spellcasting, including a multiclass wizard, but not to bard spellcasting.

13.2 Lower-Level Spells in Higher-Level Slots ​

When memorizing wizard spells, a wizard may fill a spell slot with a spell of that slot's level or any lower level. For example, detect magic, a 1st-level spell, may be memorized in a 2nd-level spell slot.

13.3 Cantrip Preparation and Memorization ​

13.4 Cantrip Capacity Examples ​

13.5 Core Cantrip List ​

13.6 Cantrip Adjudication ​

Balance principle: Preparation limits versatility; spell text limits repeatability. Daily choice allows cantrips to be more useful than purely cosmetic tricks, but any individual effect must still remain safe when cast repeatedly.

Campaign texture: Unlimited light or similar utility is a campaign-style decision, not automatically a balance failure. A wizard who devotes a preparation to the party’s lantern has made a meaningful daily choice.

14. Priest Minor Blessings ​

14.1 Preparation and Prayer ​

14.2 Core Minor Blessing List ​

Stabilization is not a Minor Blessing. Under Hovering on Death’s Door, any adjacent character may already spend one round tending the wounds with no check; a touch-range blessing would be redundant, while a ranged version would remove the intended positional risk.

15. Monster and NPC Presentation ​

15.1 Compact Template ​

Conversion discipline: A reformatted stat block should contain the same underlying values as the original monster unless a separate balance change is explicitly documented.

16. Systems Retained from AD&D 2e ​

17. 5e Systems Not Imported ​

18. Campaign Options and Deferred Decisions ​

18.1 Decision Record ​

19. Quick Reference ​

This section consolidates the rules most likely to be consulted during play.

19.1 Core Conversions ​

19.2 Combat Round ​

19.3 Weapon Speed ​

• Use the printed speed factor of the slowest weapon currently wielded and ready; two-weapon users use the slower weapon. Unarmed and natural attacks add +0.
• Subtract a magical weapon’s attack bonus from printed speed, minimum speed 0.
• Drawing or switching to a slower weapon postpones the unfinished turn if the recalculated count is later. Switching faster never improves the current round’s initiative.
• Spell casting time replaces weapon speed. Reactions are not delayed by weapon speed.

19.4 Common Actions ​

19.5 Brief Interaction and Prone Movement ​

19.6 Opportunity Attacks ​

• One reaction per round.
• Trigger: an enemy voluntarily leaves your reach.
• Make one melee attack, not a full attack sequence.
• No trigger for movement within reach, forced movement, teleportation, falling, or Withdraw.

19.7 Surprise ​

19.8 Cover, Spell Targeting, and Advantage ​

19.9 Minor Magic ​

• Wizard cantrips prepared: normal 1st-level slot capacity, minimum two; specialist bonus slots count, Intelligence bonus slots do not.
• Priest Minor Blessings prepared: total 1st-level slots including Wisdom bonuses, minimum two.
• Each cantrip or blessing takes 5 minutes to prepare and is not expended when cast.
• Minor magic uses normal components, actions, initiative, and interruption rules; Sustained effects consume the action each round.
• Core minor magic does not deal hit-point damage, heal, purify or preserve supplies, or grant direct combat bonuses.

19.10 Critical Hits ​

19.11 System Shock ​

19.12 Races and Advancement ​