Below is the very first version of these rules brainstormed in a Google Doc. The idea for this system came as a direct response to having played the Genesys Roleplaying System by Fantasy Flight. I never really enjoyed universal free-form systems and while there were certainly things I liked about Genesys I didn't love it. I wanted to know what kind of universal system I would like so I set out to make one. The Universal Action System is far from perfect and I haven't even had the chance to play it myself so it's all just theory but I still stand by the core goals I set out with when designing. A system that breaks down any possible action into its most basic parts and provides a way to resolve those actions.

At the time of this first draft, there was no dice mechanic yet. In fact, I believe in its earliest stages I didn't intend on picking a dice-based resolution mechanic at all and instead would simply provide the ABCD Action Description Framework and allow GMs to use whatever resolution mechanic they wanted. D20s, Dice Pools, Playing Cards, etc. 

There are a number of gameplay opinions that this draft discusses such as how GMs should interpret rolls and always explain the negative results of a failed roll before the player chooses to make it. I still think these opinions are valuable even though they are not represented in the current version (v1.4). I feel like, reflecting on these original ideas, the current rules sacrificed some of the intent of the design in order to gamify the dice rolling and actions. It will be interesting to see, should anyone use this system, what aspects of the rules get ignored or altered first upon being engaged with by players and GMs.

Universal Action System v0.1

Statement of Intent:

The idea behind all of this System Rambling is to create a loose and free-form style system (Which I usually hate) that is mechanically satisfying for me. This means that the “open-ended” statement forming descriptions of the player's intent system is consistently translatable into mechanical action in the game with as little of the player's intent lost in translation to the GM.

Core Mechanic:

Take actions in four parts -- Declare your intent by defining:

1. Action: Cast a Spell, Attack, Lockpick, Convince
2. Targets: Plant, Some Guy, Group, Locked door, Guard Captain
3. Range: Near, Far, Familiar, Unfamiliar, 
4. Flavor: Ice Magic, Sword, Thieves Tools, Charm, Situation Description

The GM then Increases or Decreases the difficulty based on factors relevant to each part AND also declares what the consequences will be if you fail. 

Examples:

A Florist Druid wants to A. Make Flowers Grow so they target B. An Area that is C. Near Which they flavor as D. Nature Magic

Because this is a sort of nature spell effect a GM might reduce the difficulty since the character is a druid but might increase the difficulty depending on how large the area is, a small garden, or an entire field.

A GM might decide this is easy enough for a druid and doesn’t require a roll, but perhaps a chance of failure means the magic grows briars instead of flowers.

An Assassin Rogue wants to A. Poison a drink so they target B. The Person’s Glass Which is C. Across the table and the situation is D. Visible to others

A Rogue should have excellent stealth and sleight of hand skill so sneaking poison into an unattended drink should be easy, however, A GM might determine that the Drink is out in the open and this is a large party, someone in the crowd might be very attentive of such an attempt Increasing the difficulty.

The GM could say that if the roll fails someone sees the rogue poison the drink, or perhaps someone bumps into them and they drop the vial of poison. Knowing these risks the party may decide that someone causes a distraction and begin describing a new action with its own roll that if successful would negate the increased difficulty for the Rogue.

Notes and Feedback (U.A.S.)

• Enemies and NPCs should have a much simpler resolution. Maybe just a pass-fail roll 
• Perhaps PCs could have a resource they can use to reduce the difficulty. Spellcasters could spend Strain to make a Spell easier, Fighters to hit easier, liars to be more convincing.
• If you used a dice system like FFG Narrative Dice Advantage results could be used to increase the damage, healing, number of targets, area of effect size. This is a happy extra success as opposed to declaring more damage/healing/targets/etc. Beforehand and increasing the difficulty to guarantee the bonuses. 
• Perhaps you get One action on your turn and One reaction when it’s not your turn. Reactions could be any action. You could cast a whole spell once at any time in a round. Or perhaps instead of having an AC or having enemies roll to hit you, you have to use your one reaction to describe your intent to Dodge or Block an attack making it its own action with its own roll that you have to succeed and otherwise enemies just hit.