Roll Under mod for ICRPG



Hello shield wall, I´ve been dabling with the idea of modding ICRPG to be roll-under (your attribute). I´ve searched everywhere I could and I´ve yet to find if any one has actually made such thing. For those who don´t play that way, basically you roll a check, you have to roll at your attribute or lower, 1 being critical success, if you go over your attribute, you fail, with 20 being critical failure. Hank adopted this in his last campaign last year, as per this post.

So here goes my first draft, hope we can work it up until something more or less “plug in”, for anyone interested. I believe “just” rolling under won´t quite cut it, so I made some other adjustments to the system to compliment it, some are based on the aforementioned post, some are just experiments.

Ability scores: I like the clean approach of asigning 7 points to start, so I would keep that, except all stats start at 9. This starting point could work as a “normal difficulty setting”, 8 is “hard” and 10 being “easy”.

Hearts: I found that abstracting 10hp falls appart quite fast during play, so I took the “hits, not hit points” mentallity and adapted them so each is a succesful hit, but for a hit to be succesful, it has to go over a treshold. So you start with 3 hearts, each with a treshold of 4 (3 for hard, 5 for easy). In this case, any effort roll to remove a heart has to be 4 or higher. This also allows for two distinct approaches to increasing durability, either “more hearts” or “strogner hearts”. Some may preffer having a high defense stat (more on that later) coupled with many “small” hearts, and some my preffer large armor (more on that ahead, too) and bigger hearts. It adds flexibility, and you just have to write a threshold number in your heart´s box in the character sheet to know what´s up. It works the same for “stuff” effort, such as locks, climbs, etc.

Armor: Armor should absorb damage, as to better work with the modified heart system. This allows flexibility, armor can vary by hardness, duarbility, etc. And making use of tags can also be another avenue for personalization, a “brittle” heavy armor may absorb any one full hit over its own absortion rate, but break, while a “regenrative” armor may only absorb a little bit of damage but be really hard to break, even after critical hits.

Defense: Goes to Dex + Shields
Shields: Again, an area of opportunity for better defense and flavorful tags on items.

Hard/easy: It makes more sense that somethin being hard “retracts” from your ability, and something easy “adds” to it.

Effort: stays the same, basic effort can harm a low level adventurer, as someone unaware can take one to the chin and black out. Ultimate effort can go through all 3 hearts of a starting adventurer, because of course, it is ultimate after all.

So yeah, this is my draft one, I plan to update this as I test it, as well as adapting suggestions made in this thread.



I’ve also played around with roll under for a while, here’s my concept so far:

  • Distribute 6 stat points as usual. Add 10 afterwards. Roll beneath or to meet your stat. Hence nat1 = crit. It’s a bit weird in the first place, since we’re not used to it. And due to the 10+, things get a bit easier. I’m fine with it :smiley:
  • Same goes for defense: roll beneath/meet, since higher is better as usual
  • Easy is +3 to the stat target, Hard is -3 (since lower is worse)
  • Enemys don’t roll - everything is player-facing. “the dragon’s breath is hard do dodge”, “roll to half the damage” etc.

For the rest, I stay at ICRPG’s concept since I’m a fan of short rule mods, personally :slight_smile:



Yup, pretty much, I just placed the starting stats at 9 instead of 10, so we have a bit more room for progression if the campaign goes longer.

Hard/Easy being applied according to your stat is so much more intuitive “yeah you are not fast enough so it is hard for you, -3 to the check” or “since you are clearly stronger than this gerblin, you get +3 in your check”.

The defense hacks are actually cooler IMO, because they grant different importance to both armor, shields and a PC´s dex, while complementing each other, and it works marvels with “hearts as a “treshold” instead of hearts as 10hp”.


I’m thinking of using this just to get away from having to make up target numbers for scenes, how did it work out for your group?


Hi there, I was actually doing the same thing: Stats are 9+value and all is roll under. Turns out, it did not feel much different to ‘always using a TN of12’. Not sure why, but the players did not see much of a difference between the two methods and in the end the TN12 idea took over. It also allowed to occasionally make things harder or easier and add a bit of variety. We always only use 10,12,15,18 as TNs anyway. Using a TN allowed easier conversion of some pre-made adventures out there.

Whatever you do, you have to really feel it to be able to live it. Roll under or static TN12 - personal choice.