CR to hearts



I was wondering what some of you have done for converting monsters from other games with a challenge rating CR to icrpg. just looking for input on the topic


Personally, I think that starting with 5e’s Challenge Rating is a poor foundation for your fundamental creature conversions to ICRPG, as CR is notoriously sloppy in how it weighs in monster special abilities—especially those which deal with mechanics specific and baked into 5e—when determining an overall rating; you get some really weird results with CR even within the system for which it was designed.

Instead, very generally for ICRPG Master Edition, dividing 5e’s average HP by 10 to get hearts works fairly well most of the time as a rule of thumb for ICRPG conversion, up to a certain point; occasionally you may need to buff low-level monsters and maintain a one-heart minimum in most cases. Then converted armor class approximately equivalent to the creature’s “DEFENSE” score (or appropriate Target Number guide when encountering the monster), use normal NEAR movement + action unless the old stat block has a substantial movement speed benefit, simplify damage to appropriate EFFORT categories, translate immunities/resistances/vulnerabilities more or less straight across, and simplify any special abilities to their essences, converting them to zoned ranges and keeping the damage output reasonable in cases where it otherwise might not be taken as written. That should do it.

I like to use comparative references with the “official” mosters published in Master Edition when converting creatures from other systems; compare whatever you are converting to a goblin, a skeleton, an ogre, a minotaur, or a black drake, and see if the “less powerful than/more powerful than” comparisons feel right to you. If not, adjust accordingly and look at the creature again in comparison to accepted ICRPG monsters.

Just like most editions of D&D, in 5e you will get some really ridiculous scalability problems for high-challenge creatures, so that’s when you do the comparative power method to reign in the monster’s hit points and other abilities. Do you want to be “Direhorn-tough”? Or only “Eye Beast-tough”? The comparative method is the final check to make sure a rote adherance to these suggested guidelines doesn’t give you something unplayable. When converting high-level 5e monsters, I often look at average HP; I keep them more or less the same up to about 50 HP (5 hearts), and then I start trimming (or even halving). The toughest monsters I even need to use in ICRPG tend not to have more than about 8 hearts, especially when you consider that they have resistances and special abilities.



I have a little experience with this in regard to converting one of my favorite sets of modules, colloquially known as the Wrath of Ashardalon series, from 3.0 D&D starting with the Sunless Citadel and ending with Bastion of Broken Souls.

My core concept is that I want to explore the milestone paths options in 2ed/ME. I have already pulled the Rooms/maps and rewards out for my notes, this left me with the task of rebuilding the monsters in the module. I generally ignored CR and instead focused on how many of what monster was presented in each room. I also took note of any special mechanics related to the room, such as traps or the monsters call for back up and the like.

So when rebuilding the mob for ICRPG, and mind you this is not tested just the first thing that came to my mind, I look at what makes this mob unique. Is it health, defense, special abilities/feats, etc. Whatever the case may be I highlight that ability and make sure the monster is built to showcase that thing. I then look at the health of the monster and round up to the nearest 10 which gives me a number of hearts. I then use those hearts as a trade currency for abilities that appear in the stat block, like resistance or damage reduction, spell-like abilities, etc. Sometimes it’s an even trade like 1 heart for up to DR 5. Other times it’s not like 2 hearts for a Breath weapon that does 2 dice worth of damage. It’s a judgment call on the part of the DM and a fine-tuning or adjusting in the thick of things.

One example is that the dire rats in the first module are presented as follows:

Dire Rat: CR 1/3; Tiny animal, HD 1d8+1, hp 5 (average), Init +3 (Dex): Spd 40 ft, climb 20 ft AC 15, Atck +3 melee (1d4, bite); SA Disease, SQ Scent, AL N, SV Fort +3, Ref +5, Will +3,
Str 10, Dex 17, Con 12, Int 1, Wis 12, Cha 4.
Skills and Feats: Climb +11, Hide +11, Move Silently +6, Listen+1, Weapon Finesse (Bite).
Special Attacks: Disease (filth fever): Bite, Fort save (DC 12) incubation 1d3 days, damage 1d3 Dex, 1d3 Con.

Here is my rebuild for ICRPG:

Dire Rat:___1/2 :heart: (5hp)_______Target 12 (1-3) +1TN per 4
+2 Dex, +1 Basic
+2 Bite (1d4+1) (Dex to attack)
FILTH FEVER: Con Check (Secret Roll vs TN, 1d3 days, 1d3 Dex, 1d3 Con, roll each day)

This is in contrast to a regular rat:

Rat [Super Mook]_ (1hp)____Target 10 (1-10) +1TN per 10 [see swarm]
+1 Attack
+1 Bite (1d4)

Swarm: When more than 10 rats are present increase TN by +1 per 10 rats and use swarm mechanics each Swarm has 1 :heart: and auto damages any individual unfortunate enough to start their turn in the swarm (2 damage). Reduce all damage from attacks that target a single foe to 1, normal damage from area of effect attacks.


thanks it helps a bit along with all that i got from another post some
where else


Here’s a decent thread on the subject:


thanks as always. your always so helpful in helping find things


My pleasure! Good luck with your conversions!


The following is my rebuild of the final encounter in Sunless Citadel:

TN for the final room starts at a 14
Within the final encounter is the:
Gulthias Tree :heart: :heart: :heart:
Belak human Driud :heart: :heart:
SHARWYN: human Mage (Gulthias supplicant) :heart:
SIR BRADFORD: human, Ex-Holy Warrior (Gulthias supplicant)
and 3 Twig Blights 1/2 :heart:

Most dangerous is the:

GULTHIAS TREE: Gargantuan plant :heart: :heart: :heart:
RESISTANT BARK: Reduce Weapon Effort to 1, Magic Effort to 2, and Ultimate by Half, weak to fire (double effort)
BLOOD SAP: Contact with the crimson sap acts as a mind-affecting poison, In the first round of a failed save the subject believes the tree to not be a threat, the second failed save causes the afflicted to see value in the tree and a want to protect it, the third failed save causes the afflicted to see the twig blights as allies, once all threats are neutralized the afflicted will settle into the hollow of the tree to sleep [See Suplicate].
SUPLICATE: Those who are consumed by the tree are reborn from the tree 3 turns later as a supplicant of the tree, and will give their life to defend the tree. they also can not leave a 5-mile radius of the tree, else they fall like a marionette whose strings have been cut.
ENCHANTING POLLEN: LAIR POWER, The pollen from this tree is a potent sleep poison begin each turn with a CON CHECK while in the Grove, on a failed check reduce all rolls by 1 cumulative, on a second failed check reduce movement by half, on a third failed check lose one action each turn, on a fourth failed check character becomes unconscious.