There are rules for improving a monster by adding class levels or templates, but I haven't found anything about reducing a monster's challenge rating. I'm working with only the SRD right now as I don't have access to my books.
For example, lets say we have a monster with the following relevant statistics.
Hit Dice: 7d8+21 (52 hp)
Base Attack/Grapple: +5/+13
Attack: Slam +9 melee (1d8+4)
Full Attack: 2 Slams +9 melee (1d8+4)
Saves: Fort +5, Ref +5, Will +6
Skills: Climb +9, Disguise +13, Listen +8, Spot +8
Challenge Rating: 4
Advancement: 8-10 HD (Large); 11-21 HD (Huge)
So basically I want to create a younger, or less skilled, version of this creature to ensure that the party has a fair chance -- somewhere in the CR 3 range. Using the Encounter Calculator a CR4 monster is a "Very Difficult" encounter for a party of five 1st level characters with a 270 XP rating. A CR3 critter would still be "Very Difficult", but with a 180 XP rating. I think that sounds about right.
I figure I can just reduce it's hit points by a couple of hit dice, say down to around 30-35 hit points. BAB down by a couple of points, maybe down to +3. Same for saves and skills, down by 2 points each.
Does this sound about right for a 1st level party? Are there any guidelines for reducing a monster's CR somewhere that I've missed?
For example, lets say we have a monster with the following relevant statistics.
Hit Dice: 7d8+21 (52 hp)
Base Attack/Grapple: +5/+13
Attack: Slam +9 melee (1d8+4)
Full Attack: 2 Slams +9 melee (1d8+4)
Saves: Fort +5, Ref +5, Will +6
Skills: Climb +9, Disguise +13, Listen +8, Spot +8
Challenge Rating: 4
Advancement: 8-10 HD (Large); 11-21 HD (Huge)
So basically I want to create a younger, or less skilled, version of this creature to ensure that the party has a fair chance -- somewhere in the CR 3 range. Using the Encounter Calculator a CR4 monster is a "Very Difficult" encounter for a party of five 1st level characters with a 270 XP rating. A CR3 critter would still be "Very Difficult", but with a 180 XP rating. I think that sounds about right.
I figure I can just reduce it's hit points by a couple of hit dice, say down to around 30-35 hit points. BAB down by a couple of points, maybe down to +3. Same for saves and skills, down by 2 points each.
Does this sound about right for a 1st level party? Are there any guidelines for reducing a monster's CR somewhere that I've missed?