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Convert characters and monsters from D&D to BRP
Author: Peter Brink
Added: 2006–11–09
This is just a collection of notes on how to convert AD&D and d20 characters and monsters to BRP.
Table of contents
2. Combat skills
3. Non-combat skills
4. Weapon and natural weapons damage
5. Armour Values
6. Spells
1. Stats
D&D and BRP both make use of strength, constitution, dexterity, intelligence and charisma. Convert wisdom to power.
The SIZ stat is best based on the Size (in feet) of the creature. Use the following table:
| Size in feet | SIZ | Creature sizes | SIZ |
|---|---|---|---|
| 5′ to 5′2″ | 8 | Fine | 1 |
| 5′2″ to 5′4″ | 9 | Diminutive | 2 |
| 5′4″ to 5′6″ | 10 | Tiny | 3 |
| 5′6″ to 5′8″ | 11 | Small | 4 - 5 |
| 5′8″ to 5′10″ | 12 | Medium | 6 - 21 |
| 5′10″ to 6′ | 13 | Large | 22 - 61 |
| 6′ to 6′2″ | 14 | Huge | 62 - 81 |
| 6′2″ to 6′4″ | 15 | Gargantuan | 82 - 161 |
| 6′4″ to 6′6″ | 16 | Colossal | 162+ |
| 6′6″ to 6′8″ | 17 | ||
| 6′8″ to 6′10″ | 18 | ||
| 6′10″ to 7′ | 19 | ||
| 7′ to 7′2″ | 20 | ||
| 7′2″ to 7′4″ | 21 |
For every two extra inches add 1 point of SIZ
HP is easiest converted based on the creatures SIZ (since we know it, see table above) and an average CON. You could of course roll 3d6 for CON if it’s unknown.
MP’s are either equal to Wis or 10 or 3d6 (i.e. equal to power). Some weak willed creatures, such as Kobolds, might have 2d6 POW and thus only 7 MP.
Move is equal to MV * 0.7.
The d20 Monster Manual is available on the net and can of course be used as a baseline for conversions of AD&D creatures as well. If you don’t have access to Monster Manual use the following approximation: Add 2d6 Str, Siz & Con per size class a creature is above human, subtract 2d6 Str, Siz & Con per size class a creature is below human.
2. Combat skills
The base chance of success with a combat task, in D&D, is 50%. An unskilled character must roll above or below 10 on a d20 to hit an unarmoured opponent. A level 10 fighter has a +10 bonus to this roll and thus has a 100% chance of success. The system below is designed to give an Lvl 10 warrior a skill level of 90% with his primary weapon, 80% with his secondary weapon and 70% with his third. Tthe system was originaly designed for Stormbringer 5th Ed., i.e. all weapon skills includes both parry and attack, which is why there is only one skill muntiplier value. Shields and dodge are treated as separate categories.
| Weapon Attacks | No of weapons | Base Percentile | + Per Warrior Level, Monster Hit Dice | + Per Rogue, Cleric, Monk, Level | + Per Arcane Level |
|---|---|---|---|---|---|
| Primary | 1 | 40% | +5% | +3% | +1% |
| Secondary | 2 | 30% | +5% | +3% | +1% |
| Tertiary | 3 | 20% | +5% | +3% | +1% |
| Shield | - | 25% | +5% | +3% | +1% |
| Dodge | - | 20% | +3% | +5% | +1% |
3. Non-combat skills
All normal skills have the same base chances as per the BRP game being used. Add +5% per level the nearest applicable D&D skill.
4. Weapon and natural weapons damage
Use the equivalent weapon from BRP and add damage bonus based on SIZ/STR. Natural weapons have a base damage of 1d6. E.g. a broadsword does 1d8+1 points of damage + damage bonus. Below is a list of AD&D weapons with their damage values converted to BRP.
| Weapon | Damage |
|---|---|
| Battle axe | 1d8+1 |
| Blowgun | — |
| Barbed Dart | 1d2+1 |
| Needle | 1 |
| Bow | — |
| Composite long bow | 1d8+1 |
| Composite short bow | 1d6+1 |
| Long bow | 1d8+1 |
| Short bow | 1d6+1 |
| Club | 1d6 |
| Crossbow | — |
| Hand crossbow | 1d4+2 |
| Heavy crossbow | 2d4+2 |
| Light crossbow | 1d6+2 |
| Dagger or dirk | 1d4+2 |
| Dart | 1d2 |
| Footman’s flail | 1d8+1 |
| Footman’s mace | 1d8 |
| Footman’s pick | 1d8+2 |
| Hand or throwing axe | 1d6 |
| Harpoon | 2d6 |
| Horseman’s flail | 1d4+1 |
| Horseman’s mace | 1d6 |
| Horseman’s pick | 1d6+1 |
| Javelin | 1d8 |
| Knife | 1d3+1 |
| Lance | 1d10+1 |
| Mancatcher | — |
| Morning star | 1d10+1 |
| Polearm | — |
| Awl pike | 1d12+1 |
| Bardiche | 2d6+2 |
| Bec de corbin | 1d8 |
| Bill-guisarme | 2d6+1 |
| Fauchard | 1d8+1 |
| Fauchard-fork | 1d10+1 |
| Glaive | 1d10+1 |
| Glaive-guisarme | 2d6+1 |
| Guisarme | 1d10+1 |
| Guisarme-voulge | 1d12 |
| Halberd | 3d6 |
| Hook fauchard | 1d4 |
| Lucern hammer | 2d8 |
| Military fork | 1d10+1 |
| Partisan | 1d8+1 |
| Ranseur | 1d8+1 |
| Spetum | 2d6+1 |
| Voulge | 2d6+1 |
| Quarterstaff | 1d8 |
| Scourge | 1d2 |
| Sickle | 1d6 |
| Sling | 1d8 |
| Spear | 1d8+1 |
| Staff sling | 1d10 |
| Sword | — |
| Bastard sword | 1d10+1 |
| Broad sword | 1d8+1 |
| Greatsword | 2d8 |
| Khopesh | 1d8 |
| Long sword | 1d8+2 |
| Scimitar | 1d6+2 |
| Short sword | 1d6+1 |
| Two-hand. sword | 3d6 |
| Trident | 1d8+1 |
| Warhammer | 1d6+2 |
| Whip | 1d3 |
5. Armour Values
These AP values are based on full suits of armour. In some cases this means that the fixed values are higher than in e.g. RuneQuest.
| AC | D20 | Rnd. AP | Rnd. AP - Helm | Fixed AP | Armour Type |
|---|---|---|---|---|---|
| 10 | 0 | 0 | 0 | 0 | None |
| 9 | +1 | 1 | 1 | 1 | Armour Padding |
| 8 | +2 | 1d3 | 1d3–1 | 2 | Padded |
| 8 | +2 | 1d3 | 1d3–1 | 2 | Leather |
| 7 | +3 | 1d4+2 | 1d8–1 | 5 | Ring Mail |
| 7 | +3 | 1d4+2 | 1d6–1 | 4 | Studded Leather |
| - | +3 | 1D4+1 | 1D6–1 | 3 | Treated Leather |
| 6 | +4 | 1d6+4 | 1d10–1 | 8 | Brigandine* |
| - | +4 | 1D3+3 | 1D6–1 | 5 | Chain shirt |
| 6 | +4 | 1d6+2 | 1d8–1 | 5 | Hide |
| 6 | +4 | 1d5+3 | 1d8–1 | 6 | Scale Mail |
| - | +5 | 1D5+3 | 1D8–1 | 6 | Breastplate |
| 5 | +5 | 1d6+3 | 1d8–1 | 7 | Chainmail |
| 4 | +6 | 1d4+5 | 1d10–1 | 7 | Augmented Mail |
| 4 | +6 | 1d5+4 | 1d10–1 | 7 | Banded Mail |
| 4 | +6 | 1d4+5 | 1d10–1 | 7 | Double Mail |
| 4 | +6 | 1d4+4 | 1d8–1 | 6 | Lamellar |
| 4 | +6 | 1d5+3 | 1d8–1 | 6 | Splint Mail |
| 3 | +7 | 1d6+5 | 1d12–1 | 9 | Plate Mail |
| - | +7 | 1D6+5 | 1D12–1 | 8 | Half Plate |
| - | +8 | 1D6+6 | 1D12–1 | 10 | Half Plate & Mail |
| 2 | +8 | 1d6+6 | 1d12–1 | 10 | Field Plate |
| 1 | +8 | 1d6+7 | 1d12 | 11 | Full Plate |
| - | +5 | 1D6+3 | 1D8+1 | 7 | Padded & Scale |
| - | +6 | 1D6+4 | 1D10 | 8 | Padded & Chain |
| - | +8 | 1D6+6 | 1D12 | 10 | Padded & Half Plate |
| - | +9 | 1D6+7 | 1D12+1 | 11 | Padded & Half Plate & Mail |
| - | +9 | 1D6+8 | 1D12+2 | 12 | Padded & Full Plate |
* Note that brigandine armour has been converted to a AP value based on a mean value of 7 (which is the same as the fixed value used in RQ).
6. Spells
Spells are the most cumbersome part of any conversion proccess and since one also has to convert the spells it’s also a very time consuming proccess. In fact converting magical abilities is more of an translation proccess than a conversion. In most cases the GM must, at least in part, re-create the NPC or creature being converted.
A suggestion on how to convert AD&D and d20 spells to BRP can be found here.