D&D is arguably the most common of the pen and paper RPGs and there many ways to do something similar in GURPS. GURPS Dungeon Fantasy emulates the early days of D&D where you found lots of monsters, killed them, and took their treasure. Concepts like logic, culture, and social-political dynamics are minimal if not absent entirely.
The downside to such an emulation is that it don't show GURPS major asset - flexibility. This conversion page tries to bridge the gap between D&D and GURPS and make having adventures outside of the standard pseudo medieval-early Renaissance setting (such as "City Beyond the Gate" or "Masque of the Red Death") far easier.
D&D Classes and Levels vs. GURPS Point LevelsEdit
Because of the flexibility in GURPS there is simply no way to convert a class level combo into a point total. It is better to convert concepts than actual raw power. That said there are some guidelines from B487:
- Average (25-50 points): Ordinary folk.
- Competent (50-75 points): Athletes, cops, wealthy gentry; roughly akin to level 1 in OD&D and AD&D1 and 2.
- Exceptional (75-100 points): Star athletes, seasoned cops
- Heroic (100-200 points): People at the realistic pinnacle of physical, mental, or social achievement. 150 points is about where most full-time adventurers start their careers.
- Larger-than-Life (200-300 points): Leading roles in kung fu movies, fantasy novels, etc; GURPS Dungeon Fantasy characters are 250 points.
- Legendary (300-500 points): Protagonists of epic poems and folklore. Monster Hunters are 400 points.
- Superhuman (500-1,000 points): Those who have transcended humanity and powerful creatures of fantasy.
- Godlike (over 1,000 points): True demigods
GURPS uses d6s for everything and 3d6 for attribute and skill checks. The Hypertext d20 SDR goes over the implications of changing from a d20 to a 3d6 However, unlike D&D, GURPS has an always automatic success (3 and 4) and failure (17 and 18) results if a roll can be made. Adjustments to skill can create a greater range of automatic success and failure regarding the Success roll.
One aspect of D&D attributes that makes them hard to convert is that in addition to adjusting skills most of them confer what in GURPS terms would be called advantages (or if they are low enough disadvantages).
- Strength: ST (derived GURPS attribute HP) ; Basic Lift
- Dexterity: DX; Basic Speed, Combat Reflexes, Flexibility
- Constitution: HT (derived GURPS attribute FP); Unfit/Fit
- Intelligence: IQ (derived GURPS attributes Will, Per)
- Wisdom: Will
- Charisma: Charisma, Appearance; not a requirement for being in a particular "class" (Profession template in GURPS).
Templates and Lenses (Races and Classes)Edit
Because GURPS is so detailed and flexible it is easy to become overwhelmed by the choices. To help deal with this problem GURPS provides an option called Templates and a way to create common variations called lenses. Templates come in three forms:
- Racial: a package of advantages, disadvantages, and skills a particular race has
- Character/Occupational: serves a function similar to character classes in D&D
- Meta-Traits: denote a particular state.
- Lenses: specialized templates that create an emphasis ie the Paladin and Ranger can be done as lenses of the Fighter template.
Between the two of them the Basic Set and Fantasy provide 18 race templates and undead lenses (F112-3)
Since nearly anything can become a racal template or lens, the only limitations are what the GM allows the Players to use. There are fan versions of various races available A resourceful GURPS GM could even create an “Anti-Dungeon” where the players are playing brave monsters trying to defend their home from evil adventurers!
Occupational Templates (also known as Character Templates) in GURPS generally include everything: Attributes primary and secondary, advantages, disadvantages, and skills. However in this conversion the Attribute section of such Templates has been taken care of so we are left with advantages, disadvantages, and skills. However unlike D&D GURPS skills can default to other skills, so you do not need to know as many skills as it may first appear.
This is especially true of the Melee weapon skills which don't fit D&D’s weapon categories of simple, martial, and exotic. Also skills the classes logically should have are missing (Clerics for example do not have theology). For these reasons and to simplify the conversion while adding some flexibility the D&D class templates have been modified to bring them more in line with their Medieval-Renaissance inspirations as well as adding advantages and skills better suited to role-playing. The point totals are the minimum needed to get the template.
The noted exception is the Monk as there is a huge variation in the martial styles that are available. While GURPS Martial Arts makes this far easier styles can be created with just the basic set.
Unless noted otherwise the Fantasy templates referenced are 75 points each.
Cleric [20 points]Edit
Alternative: Holy Man
Advantages : Clerical Investment , Blessed or Power Investiture , True Faith 
Disadvantages [-20]: Duty [Church/Order 12-] [-10], Vow (varies) [-10]
Skills : Crossbow, First Aid/TL, Theology, Melee Weapons (Axe/Mace, Knife, and Spear), Occultism, Shield, Throwing, Ritual Magic (skill)
Optional Advantages: Legal Immunity (w/ Diplomatic pouch)
Optional Skills: Diagnosis/TL, Esoteric Medicine, Hidden Lore, History, Literature, Naturalist, Physician/TL, Survival
Optional Wildcard Skills: Cleric!, Theurgy!
- Druid lens [+6]: You are a cleric of nature. Add Animal Handling, Naturalist, Pharmacy/TL (Herbal), Survival, Tracking, Veterinary/TL
Optional advantages: Animal Empathy, Talent (Animal Friend)
Optional Wildcard Skills: Druid!
Fighter [14 points]Edit
Skills: Armoury/TL, Bow, Brawling, Crossbow, Melee Weapons (Axe/Mace, Flail, Knife, Polearm, Spear, Shortsword, Two handed Axe/Mace, and Two-handed sword), Shield, Throwing
Optional advantages: Enhanced Defenses, Trained By A Master, Weapon Master
Optional Wildcard Skills: Blade!, Knight!, Stick!, Sword!, Whip!
- Barbarian Lens [+0] (F116): You are a fighter from one of the ‘Uncivilized’ parts of the world.
Add Basic Speed [5/0.25], Low TL [-5/TL], and Language (native speaker, illiterate) [-3]
Running, Strategy, Tactics
Optional Advantage: Enhanced Defenses (Dodge)
Optional disadvantage: Berserk
Optional Wildcard Skills: Barbarian!
- Paladin Lens [+46]: You are a warrior defender of the faith.
Add Blessed or Power Investiture (powers lost if Chivalric and/or Religious Codes broken, severe penance) , Reputation +2 (from those of Religion) , Status 2 , Comfortable Wealth or Patron , True Faith 
Vow (Chivalric Code of Honor) [-15]
Riding, Lance, Heraldry, Savoire-Faire, Ritual Magic (skill)
Optional advantages: Healing
Optional skills: Esoteric Medicine, Hidden Lore, Physician/TL
Optional Wildcard Skills: Holy Warrior!
- Ranger Lens [+6/+1]: You are fighter with an affinity with nature.
Power Investiture can be replace with Magery 0 
Animal Handling, Hiking, Naturalist, Survival, Tracking, Veterinary/TL
Optional advantages: Animal Empathy, Talent (Animal Friend)
Optional Wildcard Skills: Explorer!
Bard [17 points]Edit
Advantages: Magery 0 
Skills: Armoury/TL, Bow, Crossbow, Literature, Melee Weapons (Axe/Mace, Knife, Spear), Musical Instrument, Poetry, Public Speaking, Shield, Singing, Throwing
Optional Advantages: Legal Immunity (Bardic), Talent (Music)
Optional Wildcard Skills: Bard!
Monk [9+ points]Edit
Rogue [13 points]Edit
Skills: Acrobatics, Brawling, Bow, Climbing, Crossbow, Escape, Lockpicking/TL, Melee Weapon (Knife), Pickpocket, Stealth, Streetwise, Throwing, Traps/TL
Optional Wildcard Skills: Thief!
Sorcerer/Warlock/Wizard [11 points]Edit
Alternatives: Battle Wizard (125 pts), Hedge Wizard, Spellcaster
Advantage: Magery/Magery (Ritual) 0 
Skills: Alchemy/TL, Innate Attack (Beam/Breath/Projectile), Melee Weapons (Axe/Mace, Knife, and Spear), Thaumatology
Optional Skills: Hidden Lore
Optional Wildcard Skills: Wizard!, Magic!/Wizardry!
D&D Hit pointsEdit
Social Traits, Background, and DifferencesEdit
- Alignment doesn't exist in GURPS and therefor doesn't limit professions.
- Classes don't exist and so prerequisites for multiclassing doesn't exist.
- Control Ratings and Legality Classes are excellent tools for controlling potential bothersome spells and items; most D&D governments will be in the CR3-5 range with the occasional CR6.
- The Tech Level of the average D&D world is TL3^ to TL(3+2)^ due to the mixture of Magic and Technology.
- Languages: The default in GURPS is that a character knows how to speak as well as read and write one language natively. The cost of additional languages is based on how well they are known in both spoken and written form. D&D tends toward characters being literate.
- Wealth: Wealth is always a problem - characters either have too little of it or too much. Written for GURPS 3rd edition Incanus Color of Money provides some ideas on how to deal with wealth from a point prospective.
Converting Skills and FeatsEdit
While skills convert reasonably their expertise is a little hazier. The best solution to note what skills the character has and figure out their base level based on the information on B171-172 and especially the “Choosing Your Skill Levels” box. If you still think you need to send your skill level past 20 look at Techniques as a way improve what the character can do rather than send the skill level into orbit.
Feats are a little harder to equate as many are a mixture of built-in GURPS rules, advantages, skills, and techniques. For example, 5e feats like Heavy Armor Master, Lightly Armored, and Moderately Armored are effectively built in to the GURPS rules. The best option here to look at what the Feat does and choose the closest "fit" in GURPS terms. For example, Alert can be modeled with Combat Reflexes; Crossbow Expert can simply be high Crossbow and-or Fast-Draw skill, Healer is First Aid, and ritual caster is simply the Ritual Magic skill or Thaumatology skill.
With so many choices a few advantages and skills deserve mentioning:
One of these GURPS advantages and the Innate Attack skill is going to be your most used combination in converting D&D monsters because so many have it whether it be the crushing mandibles of a giant ant (Innate Attack), the web of a giant spider (Binding), the gaze of a medusa (Innate Attack and Affliction), or the breath weapon of a dragon (Innate Attack). The advantage is the attack itself while the Innate Attack skill is hitting something with it. The Innate Attack skill is also used for certain spells.
Also see Alchemical Items
Alchemy is the skill that is used to make elixirs (potions, powders, pastilles, and ointments). It also helps in identifying elixirs.
The spell systems GURPS allows are detailed enough that they are dealt with separately in a GURPS magic in D&D page. The general advice here is to compare how spells function effect wise rather then focusing on individual spells. For example the D&D spell Leomund’s Secret Chest is roughly equivalent to the GURPS spell Hideaway.
These two advantages are similar in that they reduce the penalties for Rapid Strike and multiple parries and are the prerequisites for a host of cinematic skills. However they differ in several key areas. Trained by a Master has a larger skill list while Weapon Master not only allows more fine tuning (from one weapon all the way up to every muscle powered weapon in the game) but it reduces skill defaults for muscle power weapons and at high skill level actually adds to damage. Usually a character will have either Trained by a Master (most cinematic Kung Ku characters) or Weapon Master (Conan, Thundarr, and Zorro) though there are a few that have both like Scorpion of Five Deadly Venoms and Xena.
Nearly every high level Undead monster and many demons in D&D will have this advantage. Unkillable 1 allows the monster to remain fighting all the way to -10*HP without a single HT roll and Unkillable 2 and 3 allow the thing to come back! Dracula in the Hammer horror films had Unkillable 3 with the Achilles Heel (wood, running water), Hindrance (wood, frozen water), Trigger (blood) limitations.
Without Industrial Enchantment powerful magic items (or items with many spells) will tend to be rare due to how the enchantment of items works in GURPS. It should be noted that Holy Objects are limited to followers of that particular deity making them more limited then their D&D equivalents.
There is conflicting information regarding the enchantment of items in GURPS Dungeon Fantasy - Dungeon Fantasy 1 specifically refers one to the Basic Set's version of the "default" GURPS Magic system of enchantment but Sean "Dr. Kromm" Punch has stated "We're saying that in books labeled "Dungeon Fantasy," Enchantment spells are off-limits because they aren't how magic items are created in GURPS Dungeon Fantasy. That genre treatment assumes that most magic items worth owning are forgotten artifacts made by lost races, ancient relics from an age when magic worked differently, gifts from gods, oddities from other dimensions, etc. The low-end ones available in shops are mass-produced by non-adventuring guilds using methods that don't closely resemble Enchantment spells. GURPS Thaumatology is full of likely candidates for the latter."
The World, Universe, and Everything ElseEdit
Converting the world itself can be in many respects the hardest part. As noted on B493 you only need to do the PC treatment of major NPCs; everybody else can pretty much be made on the spot so NPC conversion is not a problem. However world conversion can be especially difficult when modules are involved.
This is where GURPS Fantasy and GURPS Thaumatology become very useful as it will give the tools to better convert an existing fantasy world (as well as build one from scratch). There are race templates for many races and a few unique mythological characters such as Lilth (F54) and Tiamat. However before going head long into GURPS Thaumatology and GURPS Fantasy it is still best to start with the Basic Set.
Chapters 17-19 are definitely a must and here again GURPS goes into far more detail than D&D does.
The Gaming Aids page also gives some free resources that will make converting a lot easier.
The Hypertext d20 SRD site can serve a quick reference to how some abilities function in D&D to help make batter conversions to the GURPS equivalents.