The logo you just clicked on says "OGL Compatible" yet this page is titled "d20 Modern". What gives?
For a long time, I struggled to find a system that I wanted to use to represent my game. Actually, there is a longer story than that of DARK•HERITAGE. I was a fan of the notion of the OGL when it launched. I still am. I played quite a bit of DUNGEONS & DRAGONS® for quite a while when the Third Edition of the rules was released in 2000 along with the d20 licence and the Open Gaming License (OGL.) And I followed developments with both the system and the license for some time.
The truth is, though--I don't really much like D&D specifically. I had played it a bit in the 80s; both the B/X editions (various printings with various authors and covers; the differences between them were largely insignificant and esoteric, though) and AD&D in what is now "posthumously" referred to as 1e or First Edition. But I struggled with a lot of aspects of the system back then. It was a real pain and annoyance to use, frankly. And most problematically, it didn't really give me a fantasy experience that bore any resemblance to the fantasy fiction I was reading. Maybe I was reading too many of the wrong books (this is actually factually true; I didn't read any Michael Moorcock or Jack Vance until I was in my thirties, for instance.) I wandered away from D&D for many years. In fact, I wandered away from the hobby entirely, although it was always a little bit in the back of my mind. I came back into the hobby in the mid to late 90s after an absence of over ten years. By this time, however, I was thoroughly uninterested in D&D, although the fantasy genre was still my favorite one to pursue if I could. I began looking into other systems after playing a bit of Old World of Darkness and some Top Secret S.I. and Traveller, of all things.
When Third Edition D&D was set to be released, I was actually excited. The fact that it might meet my needs and be a big, popular, and easily accessible game like D&D was nice. I liked it quite a bit. The OGL/d20 licenses were a big part of the appeal; I got excited about things like Freeport or Iron Kingdoms which were in the third party sphere. I thought the release of Sword & Sorcery Studio's Creature Collection prior to the release of the Monster Manual was an amusing coup. For a time, Wizards of the Coast looked to be developing the d20 brand beyond even the D&D name. The first d20 material was the Player's Handbook which came out in August of 2000, but more material soon followed. Later in that same year, Wizards also released a Star Wars game using the d20 system. The next year, they released a Wheel of Time game using the d20 system, and the famous BRP game Call of Cthulhu was also published as a conversion into a d20-powered system. Finally, in 2002, Wizards released d20 Modern; the last of its d20 family of games. By this time, I think Wizards had definitively proven that the system was flexible, malleable, and capable of working in a variety of conditions and a variety of genres. d20 Modern, being by design a somewhat generic iteration of the system, could even be the last word; the last system one would ever need, applicable to just about any game you could concievably think to run. And, unlike the Star Wars or Wheel of Time or Cthulhu games, it was completely open content, with it's own version of the SRD, the MSRD, and the same d20 License.
Curiously, despite this, in the later years of the d20 publishing life cycle, I heard repeatedly from a number of people, the bizarre idea that D&D 3.5 was this carefully balanced system where making any changes, no matter how minor, might have broad ramifications that would unexpectedly "ruin" your game. Since this is directly counter to the actual publishing history of d20, and the obvious intent of d20 Modern in particular (which, again, really uses pretty much the exact same rules) I have no idea where this idea comes from, and it's frustrating to have to continually deal with it. But, it persists regardless.
The timing of this was good, because I was finding that the D&Disms in D&D were really starting to bug me again. d20 wasn't exactly my Holy Grail system that did everything I wanted it to perfectly (I'm not very thrilled with the combat system's reliance on grids and battlemats and prefer to do it more fast, loose and "narrative"-like; but the system kinda resists this. And the game still doesn't really work all that well at higher level, meaning that you'll probably just end up avoiding higher levels completely.) But despite this, I really resisted embracing d20 Modern, and tried to continue to mod D&D specifically to my needs.
I could look at other systems too, of course--I've given some thought to Savage Worlds, and other systems as well. But, D&D is... well, it's D&D, and there's some advantages to using it. Ryan Dancey may have introduced and made commonplace the term "network externalities" but it was a good point; it's easy to get people to play a system that they already know. And d20 proved it had the chops to do a lot of things. Honestly, I was a bit unsure until they did Call of Cthulhu and it ended up being a good game. After all, all of the rest of the games were pretty much based on pulpish action properties of some kind or another--not a bad thing, but not exactly the broadest either. So, for years, I tried to cram my settings into D&D. But D&D is not at all a generic fantasy rule-set; it's a ruleset defined by a few very specific assumptions that are not shared with the majority of fantasy (one of my early complaints with using it, actually. From back in the 80s, long before Wizards, or d20, or any of that.) Mostly, this meant eliminating a bunch of the classes, which is where D&D shows a lot of its very specific details--and replacing some of them with classes that fit the same archetype but do it in a way that's not D&D-specific. A ranger that isn't into two-weapon fighting and spellcasting, for example. Wizards who don't use Vancian fire-and-forget magic. Toning down the level of weird D&Dish wahoo in general.
For years, I also realized that I could do the same thing with much less fuss by merely adopting d20 Modern, but for some reason that just "wasn't right." Sure, it was a d20 game, and therefore almost identical in all meaningful ways to the system of D&D--just without the specific D&Disms--but I didn't go for it for a long time. Years, even. Finally I realized that that was obviously what I'd been wanting to do for a long time, even though for some subconscious reason I was avoiding it. But, by adopting d20 Modern instead of a heavily modified D&D, I found that my houserules dropped to a handful of clarifications and then new stuff that I added in specifically for DARK•HERITAGE specific flavor, like the Madness mechanic and the races. Given that, I should have made the change years ago... but instead, I had only highlighted it as one of a few "optional" rulesets to be used.
I'm not sure why I did this. It's not like I'm going to publish this, or anything. And if I did, I'd want to more firmly endorse a ruleset anyway, and I'd want to do it with the ruleset that I need to modify the least.
In any case, after much unnecessarily and prolonged deliberation with myself, I decided to whole-heartedly endorse the d20 Modern ruleset approach. I do keep this logo that I created anyways, because heck; the d20 Modern rules are OGL compatible anyway. Granted, it probably appears based on expectations that OGL compatible means D&D 3.5 compatible. The logo was specifically designed by me to echo the old d20 license somewhat, while also looking original. The reason for this was the rescindment of the d20 license. The OGL, on the other hand, is perpetual, and no matter how much Wizards may want to revoke it, they can't. So... OGL Compatible it is. This applies to material that is compatible with the SRD or the MSRD, or even, for that matter, material that's compatible with Pathfinder's PRD, or even other stand-alone games that are based on the same d20 system, like OGL Horror, or Mutants & Masterminds, or True20, or Arcana Unearthed, or whatever. It even applies, for that matter, to retro-clones, which use the SRD as the "backbone" under which non open games were cloned in the first place. But despite the broadness with which it could be applied, it's obviously meant to harken back to the old d20 logo and represent something similar, albeit unofficial--i.e. direct compatibility with either the SRD or the MSRD.