Hard Core CR Clarification



After a long hiatus, and inspired by Iron Kingdoms 5e kickstarter, I’m getting back to the table. I’ll be running a D&D 5e ruleset (because its familiar to most) + Hard Core (HC5e). After re-reading HC5e, the monster CR is throwing me off with the 1/2 cr, and high level crs.

Examples from Monster Manual 5e (MM):

Skeleton (CR 1/4)
AC 10 + 1/ 4 = 10.25 or 2.5? (MM = 13)
HP 10 x 1/4 = 3(2.5) HP - seems fine
Ck / Atk d20 + 1/4 = ?
XP 1/4 x 200 = 50 - seems fine
Of course I would mob these guys up, so would 4 Skeletons bring stats to 1?

Tarrasque (Titan CR 30)
AC 10+30 = 40 AC (MM = 25)
HP 10 x 30 = 300 HP
Ck / Atk D20 + 30 (holy shit!)
XP 30 x 200 = 6000

Should I cage CR from 1 to 10? 20? Looking for some clarification here, my friends.


I don’t know the official answer but have thought about this a bit when reading through Hardcore.

  • For things less than 1 (So anything from CR 1/8-1/2 I guess) I would just count them all as minions. 1 HP, 10AC, No bonus to rolls. XP can be like you said, and always throw them at the players in mobs. You can use the mob rules where a group of five skeletons gets +5 to hit (Which decreases as they are killed). If you want to get fiddley, say that Four 1/4 CR creatures count as one minion, so you have to kill four to reduce the mobs attack bonus by 1.

  • For the very large monster… well. I don’t think I would use them in Hardcore but something like 40AC is impossible to hit right? I would either play those monsters with totally different rules or reflavor a lower CR creature’s stats. For example the Tarrasque would not be something the players can just fight. Swinging a sword at it would do nothing. Even a fireball would not actually damage it. Instead, make those monsters a puzzle to solve. Think the ATAT walkers from Star Wars or the bosses from Shadow of the Colossus. The creature would have weak points that must be discovered and exploited. Going further, if you are playing Iron Kingdoms I would totally adapt the Chunks mechanic from ICRPG for Steamjacks. Make it feel like those big machines are something a lone adventurer can’t really fight easily, but they can be weakened and broken down piece by piece.

Just my two cents.


Thanks for putting thought into my questions.

I’m with you on the minions. thinking (o.0) Ok, yeah, so I can increase the CR if it’s say, and armored skeleton to make it different from a dusty bone minion.

Totally agree on the Tarrasque. Maybe not a good example, however, still you brought clarity on how I could tackle such a creature.

Chunks for Warjacks, totally fits, but how does it work in D&D 5e + HC and how would I calculate / create the CR? I have old IK 3.5e books, but the CR’s seem off.

I’m sure play testing may reveal some solutions as well, lol. Thanks for helping me clarify!


The vast majority of D&D monsters fall between CR 0.25 and CR 6. The 5eHCM CR “Hack” for AC really only starts to break down at CRs well above 10 or so. An ancient red dragon (CR 24) has an AC of 22, but in HC it would be 34! So, at some point, you have to nerf or cap the AC. I think this is acceptable, since higher CR monsters are really differentiated by their special attacks and abilities more than AC, whereas lower CR monsters are distinguished primarily by AC and HP.

If you look at higher CR monsters, their textbook AC doesn’t go up linearly beyond a certain point. If you really need a dragon, demon, lich, etc just nerf the AC to fit your scenario or what you think feels right. But these should be rare encounters, so don’t get too hung up on how the HC rules break down at really high levels.