From Dungeons to GURPS: Converting Classic D&D Adventures to 3rd Edition

 

Got a shelf full of classic D&D modules gathering dust? Want to run Keep on the Borderlands or Tomb of Horrors using GURPS 3rd Edition? Converting D&D adventures to GURPS is easier than you might think. Here's my complete guide to bridging the gap between these two iconic systems.

Why Convert D&D Adventures to GURPS?

D&D has decades of fantastic adventures, but GURPS offers more realistic combat, flexible character creation, and detailed skill systems. Converting lets you enjoy the best of both worlds - classic adventure design with modern game mechanics.

Character Conversion

Ability Scores to Attributes

The core six D&D abilities translate naturally to GURPS attributes:

Basic Conversion:

D&D ability scores (STR, DEX, INT, CON) = 10 + (Score - 10) / 2

Example D&D NPC has 14 STR, 12 DEX, 8 INT, 10 CON would translate to:

• ST 12, DX 11, IQ 9, HT 10
• Cap most NPCs at GURPS 15 unless they're legendary figures

Wisdom to Will Bonus Chart

• 4-5: Weak Will 3
• 6-7: Weak Will 2
• 8-9: Weak Will 1
• 10-11: Standard Will(IQ)
• 12-13: Strong Will 1
• 14-15: Strong Will 2
• 16-17+: Strong Will 3

Charisma to Appearance Chart

Here's a handy conversion for D&D Charisma to GURPS Appearance:

• 4-5: Hideous (-20)
• 6-7: Ugly (-10)
• 8-9: Unattractive (-5 points)
• 10-11: Normal (0 points)
• 12-13: Attractive (5 points)
• 14-15: Handsome (15 points)
• 16-17+: Very Handsome (25 points)

Level to Point Conversion

Convert D&D character levels to GURPS point totals:

• Using 25 points per level starting from 100:

  • Level 1: 100 points
  • Level 2: 125 points
  • Level 3: 150 points
  • Level 4: 175 points
  • Level 5: 200 points
  • etc.

Advantages and Disadvantages for Extreme Stats

When D&D characters have very high or low ability scores, Consider these GURPS advantages and disadvantages:

High Ability Scores (16+)

Strength: Lifting ST, Striking ST, High Pain Threshold 

Dexterity: Enhanced Dodge, Combat Reflexes, Perfect Balance, Ambidexterity 

Constitution: Fit/Very Fit, Disease Resistant 

Intelligence: Eidetic Memory, Lightning Calculator, Speed Reading, Language Talent 

Wisdom: Alertness, Danger Sense, Intuition, Common Sense, Strong Will 

Charisma: Charisma advantage, Voice

Low Ability Scores (6-8)

Strength: Weakness, Frail, Low Pain Threshold 

Dexterity: Bad Grip, Ham-Fisted, Klutz
Constitution: Sickly, Weak Immune System, Chronic Pain 

Intelligence: Slow Learner, Absent-Minded, Confused 

Wisdom: Oblivious, Gullibility, Weak Will 

Charisma: Social Stigma, Shyness, Odious Personal Habit

Advantages and Disadvantages Common to Each Class

Fighter/Warrior

Advantages:

• Combat Reflexes (hard to surprise, +1 to active defenses)
• High Pain Threshold (shrug off injury effects)
• Weapon Master (reduced penalties with weapon groups)
• Enhanced Parry or Enhanced Block
• Fit/Very Fit (better endurance in long fights)

Disadvantages:

• Overconfidence (rush into danger)
• Code of Honor (warrior's code)
• Intolerance (of cowards, magic-users, etc.)

Rogue/Thief

Advantages:

• Catfall (take less falling damage)
• Silence (move quietly)
• Manual Dexterity (fine manipulation tasks)
• Luck or Extraordinary Luck
• Night Vision

Disadvantages:

• Greed (can't resist valuable items)
• Kleptomaniac (compulsive stealing)
• Social Stigma (criminal background)
• Cowardice (avoid unnecessary risks)

Cleric/Priest

Advantages:

• Strong Will (resist mental influence)
• Intuition (divine guidance)
• Turning (affect undead)
• True Faith (if appropriate to campaign)
• Empathy (understand others' emotions)

Disadvantages:

• Vow (poverty, chastity, nonviolence, etc.)
• Duty (to church/deity)
• Pacifism (cannot harm innocents, etc.)
• Honesty (cannot lie)

Wizard/Mage

Advantages:

• Eidetic Memory (remember spells perfectly)
• Language Talent (read ancient texts)
• Strong Will (resist magical backlash)
• Magery (required for spellcasting)

Disadvantages:

• Absent-Minded (head in the clouds)
• Curious (must investigate mysteries)
• Weak (low physical stats)
• Social Stigma (feared/mistrusted)

Ranger

Advantages:

• Alertness (outdoor awareness)
• Animal Empathy (communicate with animals)
• Outdoorsman (wilderness survival)
• Tracking (follow trails)
• Danger Sense

Disadvantages:

• Loner (uncomfortable in cities/crowds)
• Duty (protect wilderness)
• Honesty (straightforward nature)
• Stubborn (set in their ways)

Paladin

Advantages:

• Strong Will (moral fortitude)
• Fearlessness (immune to supernatural fear)
• Charisma (inspiring presence)
• Detect Evil
• True Faith

Disadvantages:

• Code of Honor (chivalric/paladin code)
• Honesty (cannot lie)
• Vow (protect innocents)
• Intolerance (of evil)
• Selfless (put others first)

Bard

Advantages:

• Voice (+2 to reactions, singing/oratory)
• Charisma (social situations)
• Eidetic Memory (remember songs/stories)
• Language Talent
• Perfect Pitch

Disadvantages:

• Curious (love new stories/secrets)
• Compulsive Carousing (party hard)
• Reputation (known troublemaker)
• Overconfidence (talk way out of anything)

Barbarian

Advantages:

• High Pain Threshold (ignore injury)
• Berserk (fury in combat)
• Fearlessness (brave in face of danger)
• Fit (wilderness conditioning)
• Outdoorsman

Disadvantages:

• Primitive (unfamiliar with civilization)
• Berserk (lose control in combat)
• Intolerance (of "soft" civilized folk)
• Social Stigma (seen as savage)
• Impulsiveness (act without thinking)

Monk

Advantages:

• Enhanced Dodge (martial arts training)
• Perfect Balance (disciplined movement)
• Strong Will (mental discipline)
• Fit/Very Fit (physical conditioning)
• Meditation

Disadvantages:

• Vow (poverty, silence, pacifism, etc.)
• Duty (to monastery)
• Asceticism (avoid worldly pleasures)
• Stubbornness (rigid discipline)

Monster Conversion

Armor Class to Damage Resistance

• AC 10 = DR 0
• Each point of AC improvement = +1 DR
• So AC 5 = DR 5, AC 0 = DR 10

Hit Points

Use D&D HP directly, or convert based on Size Modifier and HT. Particularly tough creatures get the Extra HP advantage.

Attack Bonuses

• D&D +5 attack bonus = GURPS skill 13-14
• D&D +10 attack bonus = GURPS skill 16-17

Damage Conversion

Weapon Damage:

• 1d4 → 1d-2
• 1d6 → 1d-1
• 1d8 → 1d
• 1d10 → 1d+1
• 1d12 → 1d+2
• 2d6 → 2d-1

Trap Conversion

Converting D&D traps requires attention to detection, disarming, and effects:

Detection and Disarming

• D&D DC 15 = GURPS skill 12
• D&D DC 20 = GURPS skill 14
• D&D DC 25 = GURPS skill 16
• Use Traps skill for both detection and disarming
• Perception can substitute for detection

Common Trap Effects

Pit Traps:

• D&D falling damage converts directly (1d6 per 10 feet)
• Add spikes for +1d impaling per 10 feet
• Allow DX rolls to avoid falling, Acrobatics to land safely

Poison Traps:

• D&D Fortitude saves become HT resistance rolls
• Weak poison: HT-2, causes 1d damage over time
• Strong poison: HT-4, causes 2d damage
• Deadly poison: HT-6, causes 3d+ damage

Arrow/Dart Traps:

• Convert D&D attack bonus to skill level (+5 = skill 13)
• Use standard damage conversions
• Allow Dodge if characters are alert

Fire/Explosion Traps:

• D&D Reflex saves become DX rolls for half damage
• Typical damage: 3d6 for moderate traps, 4d-6d for large explosions

Skills and Equipment

Skill Conversion

Most D&D skills translate directly to GURPS equivalents:

• D&D skill bonus +10 = GURPS skill 14-15
• Thieves' skills become DX-based or IQ-based advantages

Treasure and Equipment

• Convert gold pieces 1:1 to GURPS dollars for purchasing power
• Magic items use standard magic item rules found in gurps magic
• Adjust prices based on campaign tech level

Adventure Structure

The beauty of this conversion is that plot, NPCs, and locations transfer directly. Focus your conversion effort on statistics rather than story elements. GURPS uses the same basic adventure framework as D&D - you're just changing the mechanical resolution system.

Quick Conversion Checklist

When converting a D&D adventure, tackle these elements in order:

1. Major NPCs: Convert ability scores, add appropriate advantages/disadvantages
2. Combat encounters: Convert AC to DR, HP directly, adjust attack skills
3. Traps: Convert DCs to skill levels, adjust damage dice
4. Magic items: Convert to GURPS enchantments
5. Treasure: Convert monetary values, keep everything else the same

Final Tips

Don't get bogged down in perfect conversions. GURPS is more detailed than D&D, but that doesn't mean every stat needs precise translation. Focus on capturing the feel and challenge level of the original adventure rather than mathematical precision.

Remember that GURPS combat is more tactical and potentially deadlier than D&D. You may want to reduce encounter difficulty slightly, especially for lower-point characters.

What's Your Experience?

Have you tried converting D&D adventures to other systems? What challenges did you face? Which conversions worked best for your group? Share your experiences in the comments below!

Which Classic Module Should We Convert First?

I'm planning a detailed conversion series - vote for which iconic D&D adventure you'd like to see fully converted to GURPS 3rd Edition:

1. Tomb of Horrors - The ultimate deadly dungeon
2. Keep on the Borderlands - Classic starter adventure
3. The Village of Hommlet - Roleplay-heavy investigation
4. The Sinister Secret of Saltmarsh - Smugglers and sea adventures
5. Secret of Bone Hill - Mystery and intrigue