From the publisher's FAQ: "Why was Action! System released under the Open Game License??
We want to encourage Action! System fans and other publishers to use the Action! System in their products, whether by publishing Action! Packed products or simply adding Action! System stats in a product developed for other systems (such as d20).
Our goals in developing the Action! System included:
* Easy entry into the hobby for new gamers (i.e., easy to learn & understand, low "buy-in" cost)
* Flexible enough to accomodate multiple genres and "power levels."
* Flexible ("modular") enough for gamers and designers/publishers to tailor the system to different specific settings without sacrificing compatibility of published Action! System material (e.g., more complexity).
* Easy for fans to use to publish their own game settings and source material using Action! System, whether for free or profit (via the Open Game License and Action! System Trademark License).
* A core system complete enough for gamers to use as-is (they may want more, but won't need more, strictly speaking)
* Flexible ("modular") enough for gamers to tailor the system to what they are most comfortable with, without sacrificing compatibility of published Action! System material (e.g., more complexity).
* Reasonable compatibility with and conversion to and from other systems.
* Rules that allow gritty realism but also encourage role-playing & dramatic action.
We feel that we reached each of those goals with the Action! System.
By releasing the Action! System Core Rules ver. 1.1 and other support material as Open Content under the Open Game License, fans and publishers can use the Open Content without requesting specific permission from Gold Rush Games. The permission is already granted in accordance with the Open Game License. "