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(Cleaning up / simplifying CR formula)
 
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== Function of CR ==
 
 
The higher the '''challenge rating (CR)''' number, the more powerful the enemy. Commonly four characters of a certain level are able to defeat one creature with a CR equal to the average level of the characters with a moderate amount of difficulty.
 
The higher the '''challenge rating (CR)''' number, the more powerful the enemy. Commonly four characters of a certain level are able to defeat one creature with a CR equal to the average level of the characters with a moderate amount of difficulty.
   
 
It can be viewed by [[examine|examining]] the creature.
 
It can be viewed by [[examine|examining]] the creature.
*'''Impossible''' (purple): 5 or more levels higher
+
*''Impossible'' (purple): 5 or more levels higher
*'''Overpowering''' (red): 3 or 4 levels higher
+
*''Overpowering'' (red): 3 or 4 levels higher
*'''Very Difficult''' (orange): 1 or 2 levels higher
+
*''Very Difficult'' (orange): 1 or 2 levels higher
*'''Challenging''' (yellow): same or 1 level lower
+
*''Challenging'' (yellow): same or 1 level lower
*'''Moderate''' (blue): 2 or 3 levels lower
+
*''Moderate'' (blue): 2 or 3 levels lower
*'''Easy''' (green): 4 or 5 levels lower
+
*''Easy'' (green): 4 or 5 levels lower
*'''Effortless''' (white): 6 or more levels lower
+
*''Effortless'' (white): 6 or more levels lower
   
 
It should be noted that these distinctions can become largely irrelevant on some [[local vault]] servers, simply because a player can edit his character at will and/or give their character items and weapons that far surpass the damage rating system.
 
It should be noted that these distinctions can become largely irrelevant on some [[local vault]] servers, simply because a player can edit his character at will and/or give their character items and weapons that far surpass the damage rating system.
 
This is also true for any server that allows a player to reach a high level because the challenge depends more on the equipment and character build than truly on their level.
 
This is also true for any server that allows a player to reach a high level because the challenge depends more on the equipment and character build than truly on their level.
   
== CR Formula ==
+
== Formula ==
The Challenge Rating of a Creature is calculated using many sources. Below is the step-by-step procedure for calculating Challenge Rating.
+
The challenge rating of a creature is calculated using many sources, most notably [[hit dice]] (HD). The additive CR is calculated by multiplying a sum by the racial challenge rating modifier, obtained from the "CRModifier" column of the row for the creature's race in [[racialtypes.2da]]. The sum in question is of the following:
  +
* HD * 0.15
  +
* (natural [[armor class]] modifier) * 0.1
  +
* [(total value of inventory items, excluding creature [[inventory slot|slot]]s) / (HD * 20,000 + 100,000) ] * 0.2 * HD
  +
* [ ([[hit point]]s before constitution and feat bonuses) / (average hit points) ] * 0.2 * HD * (creature walk rate) / ([[player character]] walk rate)
  +
* [ (total of [[ability score]]s before racial and other modifiers) / (HD + 50) ] * 0.1 * HD
  +
* [ (total of [[innate level]]s of special abilities) / (HD + 6) ] * 0.15
  +
* [ (total of innate levels of usable spells) / (HD + 1) ] * 0.15
  +
* [ (innate [[saving throw|save]] modifiers) / (base saves) + 1 ] * 0.15 * HD
  +
* [ (total of CR values of possessed feats) / (HD * 0.5 + 7) ] * 0.1 * HD
   
Add up all the following:
+
The natural armor class modifier is the modifier entered directly into the creature's properties via the Toolset. Similarly, the innate save modifiers are entered directly into the creature's properties.
   
HD * 0.15
+
The average hit points are the average hit point die rolls for each class. For example, a creature having the classes outsider 7/fighter 3 ([[d8]] and [[d10]] hit dice, respectively) would have average hit points of 7*(8 + 1)/2 + 3*(10+1)/2, which equals 48.
   
(Natural AC bonus) * 0.1
+
The walk rates are taken from the "WALKRATE" column of [[creaturespeed.2da]].
   
[ (Inventory Value) / (HD * 20000 + 100000) ] * 0.2 * HD
+
For this calculation, the innate level of level 0 spells is counted as 0.5 instead of 0.
   
[ (Total HP) / (Average HP) ] * 0.2 * HD * (Walk Rate) / (Standard Walk Rate)
+
[[category:game rules]]
 
[ (Total of all Ability Scores) / (HD + 50) ] * 0.1 * HD
 
 
[ (Total Special Ability Levels) / { (HD * (HD + 1) ) + (HD * 5 ) } ] * 0.15 * HD
 
 
[ (Total Spell Levels) / { (HD * (HD + 1) ) } ] * 0.15 * HD
 
 
[ ((Bonus Saves) + (Base Saves)) / (Base Saves) ] * 0.15 * HD
 
 
[ (Total Feat CR Values) / (HD * 0.5 + 7) ] * 0.1 * HD
 
 
then multiply the total sum by the racial challenge rating modifer, the CRModifier value from racialtypes.2da, using the creature's race as an index into the 2da. The resulting value is the Additive CR.
 
 
<u>Terms Used Explaination</u>
 
 
HD = Hit Dice = total number of levels the creature has in all of its classes.
 
 
Natural AC Bonus
 
 
Inventory Value = total value of all items in the Creature's inventory, not counting items equipped in the creature weapon slots or the creature hide slot. See Section 4.4 of the Items document for how to calculate item cost.
 
 
Total HP = total hit points, not including bonuses from constitution or feats.
 
 
Average HP = average hit points based on average hit point dice rolls for each class. For example, a creature having classes Outsider 7/Fighter 3 (d8 and d10 hit dice, respectively) would have Average HP = [7 * (8 + 1)/2] + [3 * (10+1)/2] = 7*4.5 + 3*5.5.
 
 
Walk Rate = creature's walk rate from the WALKRATE column of creaturespeed.2da, using the creature's WalkRate GFF Field as the 2da row index.
 
 
Standard Walk Rate = The WALKRATE column value for row 0 in creaturespeed.2da, which corresponds to player characters' movement rate.
 
 
Total of all Ability Scores = total of all ability scores, before any modifications due to race, feats, or equipped items.
 
 
Total Special Ability Levels = total levels in all special abilities in the creature's SpecAbilityList GFF List. For each spell in the special ability list, get its Innate value from spells.2da, and add that to the total special ability levels.
 
 
Total Spell Levels = total levels of all spells in all the spell lists in all the creature's classes. The level of a spell is taken as its Innate value from spells.2da. If the Innate level is 0, then count it as 0.5.
 
 
Bonus Saves = total of the creature's fortbonus, refbonus, and willbonus GFF Fields.
 
 
Total Feat CR Values = total CR Values of all feats that the creature has. The CR Value of a feat is its value under the CRValue column in feat.2da" (bioware,
 
[[Category:Game rules]]
 

Latest revision as of 08:11, September 11, 2009

The higher the challenge rating (CR) number, the more powerful the enemy. Commonly four characters of a certain level are able to defeat one creature with a CR equal to the average level of the characters with a moderate amount of difficulty.

It can be viewed by examining the creature.

  • Impossible (purple): 5 or more levels higher
  • Overpowering (red): 3 or 4 levels higher
  • Very Difficult (orange): 1 or 2 levels higher
  • Challenging (yellow): same or 1 level lower
  • Moderate (blue): 2 or 3 levels lower
  • Easy (green): 4 or 5 levels lower
  • Effortless (white): 6 or more levels lower

It should be noted that these distinctions can become largely irrelevant on some local vault servers, simply because a player can edit his character at will and/or give their character items and weapons that far surpass the damage rating system. This is also true for any server that allows a player to reach a high level because the challenge depends more on the equipment and character build than truly on their level.

Formula Edit

The challenge rating of a creature is calculated using many sources, most notably hit dice (HD). The additive CR is calculated by multiplying a sum by the racial challenge rating modifier, obtained from the "CRModifier" column of the row for the creature's race in racialtypes.2da. The sum in question is of the following:

  • HD * 0.15
  • (natural armor class modifier) * 0.1
  • [(total value of inventory items, excluding creature slots) / (HD * 20,000 + 100,000) ] * 0.2 * HD
  • [ (hit points before constitution and feat bonuses) / (average hit points) ] * 0.2 * HD * (creature walk rate) / (player character walk rate)
  • [ (total of ability scores before racial and other modifiers) / (HD + 50) ] * 0.1 * HD
  • [ (total of innate levels of special abilities) / (HD + 6) ] * 0.15
  • [ (total of innate levels of usable spells) / (HD + 1) ] * 0.15
  • [ (innate save modifiers) / (base saves) + 1 ] * 0.15 * HD
  • [ (total of CR values of possessed feats) / (HD * 0.5 + 7) ] * 0.1 * HD

The natural armor class modifier is the modifier entered directly into the creature's properties via the Toolset. Similarly, the innate save modifiers are entered directly into the creature's properties.

The average hit points are the average hit point die rolls for each class. For example, a creature having the classes outsider 7/fighter 3 (d8 and d10 hit dice, respectively) would have average hit points of 7*(8 + 1)/2 + 3*(10+1)/2, which equals 48.

The walk rates are taken from the "WALKRATE" column of creaturespeed.2da.

For this calculation, the innate level of level 0 spells is counted as 0.5 instead of 0.

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