What Do Bethesda and Gygax Have In Common?

I have spent a lot of hours on the Elder Scrolls series. The latest entry in that series, Skyrim, is a great game and I have clocked in well over 500 hours. Still, after all of that play time, I enjoy the game and continue to return to it, choosing it over newer games in my collection. I think it is a testament to how compelling a game is when its 500th hour is more entertaining than the first hour of another game.

In short, I love Skyrim (and all of its predecessors). And yet, when you examine it closely, Skyrim is a pretty crappy game. Take its combat system, for instance. It is pretty much a click-fest with very few moves or tactical depth. Most fights can be won by click-spamming, or at higher difficulties, click-spamming with potions. The spell system doesn't scale with the game as you level up and lacks, of all things, interesting spells. The crafting system was obviously an afterthought that starts out mostly pointless and ends up absolutely game breaking.

Still, Skyrim is an awesome game that transcends any of its uninspiring subsystems. As an armchair designer, I find this phenomenon fascinating. I immediately wonder how this applies to tabletop games. What games out there are a mass of mediocre systems that somehow manage to become much greater than the sum of their parts?

And of course, the answer is staring at me from my shelf... and the annals of gaming history. Advanced Dungeons and Dragons is that game: a mash of systems, none of them particularly good, cobbled together to form a game that is brimming with awesome. I spent countless hours in countless basements playing sessions of AD&D. I have read those books 100 times or more. It is a great game, but taken one system at a time, the hit points, the Vancian magic, the god-awful weapon/armor class to hit matrix, descending armor class, the grappling and psionics rules... ugh.

Now, there are tons of reasons for both Skyrim and AD&D to have been so successful, even considering their flaws. But I wonder if the flaws haven't actually helped both games become even more successful than they might have otherwise. In the case of Skyrim, an extensive modding community exists where people have done everything from adding items and quests, to releasing unofficial patches to reworking almost all aspects of gameplay. My Skyrim is very different from the vanilla version, personalized to my taste and better in almost every way.

In the case of AD&D, the customization is more DIY. How many new classes, spells, monsters, alternative combat systems... and ultimately games have I created? More than I would like to admit, really. Heck, you could easily argue that the imperfections of D&D spawned an entire industry!!

So, what about your experiences? Do you have any examples of "great games with terrible systems?" If so, what do you love about these games?