99 – d20 Conversion Rules

Skills

Most of the Pathfinder skills have a one to one relationship with Hero. Hero however adds many new skill options to expand on further character definition. However, to ensure compatibility with adventures here are some important things to note:

  • Acrobatics is used for aerial maneuvers, flips, and jumps
  • Appraise is a Professional Skill
  • Breakfall is used for floor work, tumbles, and falling
  • Concelament is gone. Perception is used for searching.
  • Craft Skills are mapped to Pathfinder. This is a new class of skill and has a Skill Enhancer (Craftsman) to go with it.
  • Criminology can give you a bonus when looking for clues and such and enhances PER in some cases. 
  • Disable Device maps to Security Systems
  • Heal includes Paramedics and Forensic Medicine
  • Interrogation is renamed Intimidate. It compliments PRE attacks to do either.
  • Knowledge Skills are mapped to Pathfinder.
  • Languages are set. Literacy is assumed (take a 5pt complication if you are illiterate).
  • Linguistics is a Knowledge Skill (for the language portion), Cryptography for cyphers, and Forgery for forging documents.
  • Mechanics is now covered by Craft skills.
  • Professional Skills are mapped to Pathfinder.
  • Science skills are unused
  • Sense Motive is a function of Conversation.
  • Spellcraft is a new skill based on INT.
  • Use Magic Device is a new skill based on PRE

Difficulty Class (DC)

DC 5 = +3
DC 10 = +2
DC 13 = +1
DC 15 = +0
DC 16 = -1
DC 18 = -2
DC 20 = -3
DC 23 = -4
DC 25 = -5
DC 28 = -6
DC 30 = -7
DC 33 = -8
DC 35 = -9
DC 38 = -10
DC 40 = -11

Environmental Damage

In general, look at the max damage and divide by 3. That is the number of DCs. You decide if it is killing or normal.

Breaking Things

Breaking things is tricky. Hero already has a well defined system for that. However, when it comes to effects like “Characters can escape the sinking sand by making a DC 23 STR check” this table gets it done. Break Effect means total BODY on the STR dice.
DC
Break Effect
10
2
13
3
18
4
23
5
25
6
28
7
30
8
33
9
35
10
38
11
40
12
43
13
45
14
48
15
50
16

Challenge Rating (CR)

Converting CR is a bit challenging. However, since the characters advance along a tight set of guidelines it is easiest to convert Challenges according to the table below. The point value of the Challenge is less relevant than the overal impact on the characters, and so specific guidelines for the point value of a Challenge are not given, although the total point value of the adventuring party is a good estimate of an equal challenge, assuming these guidelines are followed. 
These values represent the maximum values for a dedicated combatant (i.e. Fighter-Type in d20). Non-fighter types convert as follows:

Wizards: OCV/DCV 1/2 values, Defenses  1/3 values

Rogues: OCV 2/3 values, Defenses 1/2 values

Clerics: OCV 2/3 values, DCV 2 rows up, Defenses 2/3 values (but often max)

Evens so, these are just a guidelines and not a hard rule. 
DR: Damage Reduction added as a power (typically Physical and Energy, Resistant)
rPD/rED Bonus: Bonus to rPD/rED above campaign limits

Characteristics Powers        d20 Conversion

Base

SPD
OCV/
DCV
OMCV/
DMCV
PD/ED/
Mental
rPD/rED/
Power

DC

Skill
Standard
Active
Complex
Active

CR
Attack
Bonus

AC

HP

STUN

DR
rPD/
rED
Bonus

BODY
13 3 5 4 6 5 6 12- 45 18 < 1 3 15 2 25     13
14 3 5 4 6 5 6 12- 45 18 1 4 16 5 30 14
15 3 5 4 6 5 6 12- 45 18 1 5 16 10 30 15
15 3 5 4 6 5 6 12- 45 18 2 6 17 15 35 15
16 3 5 4 6 5 6 12- 50 20 2 7 17 20 35 16
17 3 5 4 7 5 6 12- 50 20 3 8 18 25 40 17
18 3 6 5 8 6 6 12- 50 20 3 9 18 30 40     18
19 3 6 5 8 6 6 12- 50 20 4 10 19 35 40 19
20 3 6 5 9 6 6 12- 55 22 4 11 19 40 40 20
20 3 7 6 10 7 7 13- 55 22 5 12 20 45 45 20
21 3 7 6 10 7 7 13- 55 22 5

 13 20 50 45 21
22 3 7 6 11 7 7 13- 55 22 6 14 21 60 45 22
23 4 8 6 12 8 8 14- 60 24 6 15 21 70 50     23
24 4 8 6 12 8 8 14- 60 24 7 16 22 80 50 24
25 4 8 6 13 8 8 14- 65 26 7 17 22 90 50 25
25 4 9 7 14 9 9 15- 65 26 8 18 23 100 55 25
26 4 9 7 14 9 9 15- 70 28 8 19 23 110 55 26
27 4 9 7 15 9 9 15- 70 28 9 20 24 120 55 27
28 5 10 8 16 10 10 16- 75 30 9 21 24 130 60     28
29 5 10 8 16 10 10 16- 75 30 10 22 25 140 60 29
30 5 10 8 17 10 10 16- 75 30 10

 23 25 150 60 30
30 5 10 8 17 10 10 16- 75 30 11 24 26 160 60 30
30 5 10 8 17 10 10 16- 80 32 11 25 26 170 60 30
30 5 10 8 17 10 10 16- 80 32 12 26 27 180 60 30
31 5 11 8 18 11 11 17- 80 32 12 26 27 190 65     31
31 5 11 8 18 11 11 17- 80 32 13 27 28 200 65 31
31 5 11 8 18 11 11 17- 85 34 13 27 28 210 65 31
32 5 11 8 19 11 11 17- 85 34 14 28 29 220 65 32
32 5 11 8 19 11 11 17- 85 34 14 28 29 230 65 32
32 5 11 8 19 11 11 17- 85 34 15 29 30 240 65 32
33 6 12 9 20 12 12 18- 90 36 15

 29 30 250 70 25% +1 33
33 6 12 9 20 12 12 18- 90 36 16 30 31 260 70 25% +1 33
33 6 12 9 20 12 12 18- 90 36 16 30 31 270 70 25% +2 33
34 6 12 9 21 12 12 18- 90 36 17 31 32 280 70 25% +2 34
34 6 12 9 21 12 12 18- 95 38 17 31 32 290 70 25% +3 34
34 6 12 9 21 12 12 18- 95 38 18 32 33 300 70 25% +3 34
35 6 13 10 22 13 13 19- 95 38 18 32 33 315 75 50% +4 35
35 6 13 10 22 13 13 19- 95 38 19 33 34 330 75 50% +5 35
35 6 13 10 22 13 13 19- 100 40 19 33 34 345 75 50% +6 35
36 6 13 10 23 13 13 19- 100 40 20 34 35 360 75 50% +7 36
36 6 13 10 23 13 13 19- 100 40 20

 34 35 375 75 50% +8 36
36 6 13 10 23 13 13 19- 100 40 21 35 36 390 75 50% +9 36
37 7 14 10 24 14 14 20- 105 42 21 35 36 405 80 50% +10 37