Best way to Lower Monster CR

[Dormammu]

What's the best way to lower a Monster's CR? I find as a GM I'm constantly wanting to use cool monsters but can't because the PC's are too low level.

But is there another way? I suppose I could just subtract X from BAB, saves etc. then remove overpowered abilities, but how much? What's a good rule of thumb?

Feel free to point me to another thread if this has been answered already.

[sideswipe]

remove unique and overpowered abilities.

a lot of monsters have one particular ability that just screams its CR. and without it it would be average, im looking at you rhemoraz and your 8d6 heat damage each round for free!

monsters that have a tonne of hp and no real attack power, lose some HD and call it a day. then there offensive power scales up a bit and a lower CR

[atemu1234]

I recommend first running it through Vorpal Tribble's CR calculator (google it, I think it should show up) and then removing stuff it increases it's CR for.

[Shoat]

If you want to do it without touching the stat block:

- Give the monster an unfavorable combat situation (PCs are specifically prepared for it's weaknesses, bad terrain/weather/etc., PCs have NPC allies, Monster has more difficult objective other than "smash enemies", Monster wants to not only survive but also preserve some abilities for the rest of the day, etc.)
- Or reduce it's AI (have it fight less intelligently).


Otherwise, do what I'd do if a player wants to play a cool monster PC:

- Remove every ability that is not specifically associated with the monster's theme (abilities that add JUST power and no "cool", such as the summon ability most fiends have), but be sure never to remove fully-unique abilities as many monsters are thematically built around them
- Then replace as many of the leftover traits&abilities with more reasonable ones for the level you desire (example: rhemoraz's free 8d6 heat damage -> X/day activatable ability that does a heat burst for one round with adjusted lower damage / succubus change shape at will -> replace with disguise self or alter self depending on level)
- Then lower numbers (be it HD or the specific numbers of leftover abilities) until you feel it's fine.

[Ettina]

My GM did it by halving all the monster's stats. Simplistic, but it worked.

[Urpriest]

There's a huge number of monsters and monster customization options in 3.5. Almost always there's a lower-CR monster that will fill the role better.

[Psyren]

- Apply a template that weakens them, like Young. (http://www.d20pfsrd.com/bestiary/monster-listings/templates/simple-template-young-cr-1) (This does not have to mean they are actually children - it can also refer to frail or runty yet full-grown specimens,)
- Apply an affliction before the fight starts. Maybe that manticore accidentally gobbled up some poison, or maybe that beholder picked up a cursed ring.
- Favorable terrain for the PCs, like fighting a light-sensitive creature outdoors during the day, or fighting a large creature in tight quarters, or a flying creature in a low-ceilinged area.
- As a last resort, have an NPC around to help. Say there is a gang of ogres with a tied-up dryad, arguing over how to cook her. If the rogue can stealth over there and remove her gag, she can hit one of her jailors with charm or suggestion, allowing the PC group to take on the rest with improved odds.

[Dormammu]

Thanks everyone! I think I'm going to take an amalgamation of all the above suggestions, then put it in the CR calculator thanks again!