Played more Deus Ex, though curiously that has not really been what's been eating my time. I've really grown to appreciate it's design of creating multiple paths to success, and what's most interesting to me is that those paths remains mostly obscured unless you're the kind of player who cheerfully spends time poking into every nook and cranny (which I am).
But the thing that's impressed me is something that resonates very well with adventure design. There's an old saying which I think I heard from S. John Ross, that a mystery should be like a maze - confusing if you're in it, even if it's obvious from up above. I've always liked that comparison because it speaks to one of the biggest challenges to the GM in designing coherent adventures - the GM is always looking at the maze from overhead, so it's hard to really wrap your head around what it looks like from within.
A lot of bad habits come from this, and two of them in particular are a poor sense of difficulty (that is - "my players are such idiots, why can't the see the obvious!") and railroading ("There's a path out of the maze, I just need to get them on it!").
Now, there are a lot of solutions to these problems, and I've talked a lot about flexible ones such as might be used in Leverage, but if you like your structured adventures, there's still something interesting to do about it. Thats where Deus Ex comes in.
At first my GM's instincts twitched in the face of Deus Ex mission design. Sure, it was great to have it be objective (rather than process) driven, but when you started looking around, you realize there are SO MANY ways to approach a problem that it seems unfair - it's _too easy_. But at the same time, I was impressed at how tidily the various approaches knitted together to feel organic.
The piece I was missing was that the organic feel was a natural offshoot of their being too many options. Even if there are multiple paths of approach, the player will only experience one, and by virtue of doing so, it will feel right. There's some interesting thinking there - if we figure out to do some clever jumping to get somewhere, we credit the designers for foreseeing that. And, heck, maybe they did, but more likely, they didn't stop it.
See, that's the real trick - though there are multiple paths to the goal, what really makes them work is that the player can change paths at will. You are not compelled to keep sneaking even if you have been sneaking up to this point.
This is the point that intersects with adventure design interestingly. There's a tendency in structured designs to dig tunnels - single paths to the destination. A "flexible" design might have multiple discrete tunnels, but discrete is the operative word. Writers and GMs will regretfully accept the necessity of this approach because, without a tunnel, there's no telling which way the characters will go.
A game like Deus Ex forgoes tunnels in favor of trenches. The trenches all flow towards the end point on various routes which the player can easily follow, but they are also easy to step out of and into a different trench. The net effect is a sort of mesh design which has some fascinating emergent properties. Specifically, by making the process through them non-procedural, it feels more player driven and organic, and provides opportunities for meaningful out-of-combat choice and strategy. Yes, all trenches may get you where you're going eventually, but you can still be smart about picking which ones to follow.
Anyway, I have more to play, and I expect it to continue to be fun, but I just want to plant that idea in your ear: Mesh Design. It's worth a try.
1 - How do they do this? By being built _out_ from the goal. Building a maze from the outside in is a novice mistake.