Ok this is what I want...

1 No skills, disadvantages, advantages, perks, quirks, talents, etc.
2 Only attributes with no modifiers to attributes...
a. I only want to use the full attribute number.
3 roll under but test with a d20 not 3d6
4 classless
5 level-less

GURPS can do this, yes?
Any other ruleset that does this?

Basic ICRPG does all this but #3.  It's a roll over rather than a roll under.

Quote from: briansommers on February 19, 2025, 11:08:12 PMOk this is what I want...

1 No skills, disadvantages, advantages, perks, quirks, talents, etc.
2 Only attributes with no modifiers to attributes...
a. I only want to use the full attribute number.
3 roll under but test with a d20 not 3d6
4 classless
5 level-less

GURPS can do this, yes?
Any other ruleset that does this?

No, GURPS is full of #1, and you only have 4 attributes, which would make a very bland game with your #2 and #3.
If read correctly your list, a character is, rulewise, only defined by its set of attributes... not very fancy, no ?

Easily use D&D attributes with d20 roll under and ignore the rest.

In fact, if you need more attributes, there's Players Option: Skills & Powers where you can run variant chassis. One of them takes the core six and adds a split of each stat which can be adjusted oppositional up to a difference of four, thus allowing for gradations of attribute checking. e.g. Constitution 13 can be split into a Health 11 and Fortitude 15, so Health is how well you resist a cold or food poisoning whereas Fortitude is how much physical punishment your body can endure. Six primary attributes with 12 refined sub-attributes allows for a D&D that can be run as full attribute checks, if you want and can ignore the rest.

It was D&D all along!
/sung to "It Was Agatha All Along"

As an exactly as designed extant RPG? Can't immediately think of one that caters to this chassis, especially since it's an easy to adopt general system out of most RPG design that has stats. Though there are oodles of heartbreakers out there so it probably does already exist, likely in a charity bundle or itch,io.

S John Ross pointed out there are only 12 basic things characters do in an adventure,

• Athletics
• Persuading
• Communicating
• Detection
• Driving
• Gadgeteering
• Medical
• Wilderness
• Scholarship
• Intrusion
• Combat
• Magic

Make these a list of 12 attributes.

For any system using a dX, roll up a character by rolling 2dX and taking the lowest, that's the level of the  attribute.

When a player wants their character to do something, decide which attribute is relevant, and have them roll dX under their attribute. If it's contested, then both parties to the contest roll, and whoever gets the greatest margin of success, or lowest margin or failure, wins the contest. Equipment, circumstances etc may add to the attribute.

There you go.

GURPS definitely can't do that because of #3, one of the things it got right. 

An afterthought: check
https://www.neoclassicalgames.com/product-page/neoclassical-geek-revival
It's almost class-less and skill-less, and relies mostly on attributes rolls (I don't remember if it's under or over...).
A little gem of new-wave OSR, I would say.

Quote from: Kyle Aaron on February 20, 2025, 06:03:10 AMS John Ross pointed out there are only 12 basic things characters do in an adventure,

• Athletics
• Persuading
• Communicating
• Detection
• Driving
• Gadgeteering
• Medical
• Wilderness
• Scholarship
• Intrusion
• Combat
• Magic

Make these a list of 12 attributes.

For any system using a dX, roll up a character by rolling 2dX and taking the lowest, that's the level of the  attribute.

When a player wants their character to do something, decide which attribute is relevant, and have them roll dX under their attribute. If it's contested, then both parties to the contest roll, and whoever gets the greatest margin of success, or lowest margin or failure, wins the contest. Equipment, circumstances etc may add to the attribute.

There you go.

This is the way. Sounds like you don't really need a published system, since you're looking for super bare-bones. You've basically already created it by stating what you wanted.

Quote from: Kyle Aaron on February 20, 2025, 06:03:10 AMS John Ross pointed out there are only 12 basic things characters do in an adventure,

• Athletics
• Persuading
• Communicating
• Detection
• Driving
• Gadgeteering
• Medical
• Wilderness
• Scholarship
• Intrusion
• Combat
• Magic

I wouldn't normally be in this thread because it's about classless RPGs, but seeing a proposal to make all of these activities equally weighted raises my eyebrows.  There's also a strong case to be made that there is no difference between persuading and communicating.  Regardless though, you'd be hard pressed to find a game that spends as much time on an athletics minigame that it does on a combat minigame, and for good reason.

Quote from: Venka on February 20, 2025, 10:49:53 AMThere's also a strong case to be made that there is no difference between persuading and communicating. 

I believe Communicating is the sharing of information (like picking up or spreading rumours), while Persuasion is pushing for an outcome.

Quote from: Kyle Aaron on February 20, 2025, 06:03:10 AMS John Ross pointed out there are only 12 basic things characters do in an adventure,

• Athletics
• Persuading
• Communicating
• Detection
• Driving
• Gadgeteering
• Medical
• Wilderness
• Scholarship
• Intrusion
• Combat
• Magic

Make these a list of 12 attributes.

For any system using a dX, roll up a character by rolling 2dX and taking the lowest, that's the level of the  attribute.

When a player wants their character to do something, decide which attribute is relevant, and have them roll dX under their attribute. If it's contested, then both parties to the contest roll, and whoever gets the greatest margin of success, or lowest margin or failure, wins the contest. Equipment, circumstances etc may add to the attribute.

There you go.

Players are also going to need to know when characters are healthy, injured, or dead. A simple "3 strikes" approach can address this (e.g. lightly wounded --> critically wounded --> dead), but this would also make every character/critter equally tough. The only determining factor would be how easily they are to get hit; a product perhaps of their Combat attribute.

Otherwise, some form of "fortitude" attribute is in order. Using the above list, an argument can be made that Athletics can contribute to health (addressing the concerns Venka brought up).

Honestly, though, if you're going as bare-bones as the OP suggests, I question why even have attributes at all. Just make everything an opposed contest, applying modifiers as appropriate. Depending on the circumstance, the opposing die may represent either the foe's skills or the will of fates, but the actual game mechanic remains the same.

Quote from: Venka on February 20, 2025, 10:49:53 AMseeing a proposal to make all of these activities equally weighted raises my eyebrows.  There's also a strong case to be made that there is no difference between persuading and communicating.  Regardless though, you'd be hard pressed to find a game that spends as much time on an athletics minigame that it does on a combat minigame, and for good reason.

They're equally-weighted because the OP just wanted "attributes". If you started breaking down "combat" into punching, kicking, wrestling, bladed weapons, blunt weapons, handguns, blah blah, then you don't have attributes any more, you have a skill system.

In Ross's original layout he gave some description. "Persuading" includes intimidation, seduction, bargaining, begging and so on. "Communication" includes various languages, protocol and culture.

"Athletics" includes running, jumping, climbing, swimming etc. Again you can break them down further but then you've got a skill system, which the OP didn't want.

I find this is an issue in the fitness forums I frequent, too. A person asks for X. I offer X. Then people pipe in and go "yeah but what about Y and Z? And shouldn't X include A and B?" I was not answering "what do you think is an ideal rpg system?" I was answering the OP's question. I realise this is unusual on the internet, what can I say but that I grew up without the internet where we actually had a dialogue rather than alternating unrelated monologues. I'm a reactionary, I know.

Is there a system that is both class-less and skill-less?
Without classes the skills are generally how you define your PC.

I was going to say The Black Hack, but it is a class based game.

Cairn.  That's a classless game without skills, advantage/disadvantage, or perks.

It's also free.

Cairn Website

It's an odd game as it actually could be described as, "You are what you wear."

In other words, it's a gear based game.  If you got a lot of armor and a big sword, you're the warrior.  But, if you go out next time wearing robes and devote all of your gear space to a bunch of spellbooks, your the wizard.