Oryan77 said:
But now that even players know D20 rules so well because they are so easy to learn, I find it hard sometimes to make a scenario more stimulating & exciting.
You hold 99% of the cards -- the players don't know the dungeon, the NPCs, or any of the items, magic or otherwise, that they're finding. How could you possibly need even more control than that? I think you're selling yourself short - my guess is that you might be accomplishing your goal more than you think.
Oryan77 said:
I will think of a really clever & unique action for a character to do, only to find out that because of one miscellaneous rule, I can't do it without breaking the rules. I can't get away with it because the players will catch me
Most (almost all, really) of the rules exist within a framework. That framework includes, for example, the "circumstance modifier". The circumstance modifier is a bonus or penalty that you assign to any dice roll for pretty much any reason whatsoever. Anything that has a convincing reason to happen in your campaign should be able to be articulated as a justification for a bonus/penalty. Without examples there's not much more I can say.
Oryan77 said:
Sometimes as a DM, I will do something that I know will scare players into thinking the situation is going to be bad, but I don't have the intention to actually screw them over.
If you just ran the game and let the dice fall, the dice would screw them over periodically and then they actually would be scared just sitting down to play. However, if you insist on maintaining 100% control over everything that will happen, then it will take them at most about 2 game sessions (IME) to figure out that nothing bad will ever happen. Ex: see "Boy who cried wolf". The lesson is that people learn (eventually).
Oryan77 said:
I just want to make them think they are screwed so when they thwart my attempts, they will feel even more heroic. But it sucks when a rule gets in my way.
All rules, by definition, get in your way of doing this, because all rules define the chance of success/failure. The only thing you have going for you is that the players don't usually know the relevant stats. Though you're probably giving them information that they shouldn't know. In your example - they just shouldn't know what kind of weapon an NPC is using against them in order to realize that Sunder doesn't apply.
What's scary to people (and interesting/worth exploring) is the UNKNOWN. And if you're just going to turn over the equipment lists of your NPCs to the players when they encounter them, you're not using what you have.
Oryan77 said:
When I announce that the NPC attacks her bow and she gets an AoO, she freaked out, "WHAT?! MY BOW?! What the hell am I going to do if I lose my bow! CRAP!". She was genuinely worried.
Mission accomplished then. What else do you want. If you just wouldn't have blabed about what kind of weapon your NPC was using, you could have rolled dice behind your screen all night, cackled evilly, and no one would have been the wiser. You went ahead and (apparently) told the players all about your NPC's equipment before they earned the right to that information. You failed to sunder the bow - that round. That's all the players needed to know.
Oryan77 said:
Then the players rejoice.
First fear, then rejoice?! And your'e not happy? How much control do you want? You got what you wanted from what I can tell.
Oryan77 said:
So I suck it up, and try to think of other ways to be "original" and get the players nervous so they can reminisce about that moment later on.
You know one thing that would be "original" would be if a PC sat down to a plate of stew, and stabbed himself to death with his spoon while eating it. That would also suck though, and I think what players are expecting is for the rules so make some sort of sense.
Oryan77 said:
I also see it happen with players. Sometimes a player wants to do something clever and he can't because he lacks some stupid feat or something.
If the feat is that stupid then change it! If the rules say that you can't jump more than 5 ft horizontally without a feat, then that's clearly stupid and I have no idea how you'd lose anyone's trust by house-ruling it.
On the other hand, if the PC wants to jump 200 feet horizontally and you decide that it's a good idea just because it's Tuesday and you've been watching Spiderman movies all day, then you'd probably be in trouble. The nature of the DnD game, IMO is that the rules are codified for a reason. The role of the DM is to facilitate an exploration of a shared fantasy world according to a set of common rules.
Maybe Action Points are in order here. The down-side to Action Points is that they're still rules, which means you'll still be constrained by whatever rules govern them. IMO there's just no way to avoid learning how to work within a rules system if you're going to DM something that you want people to believe is a game.
Look - DnD could have been a lot simpler if the rulebook consisted of a single page that said "Rule 0: The DM tells you what happens, the end." The rules, the dice, the prewritten scenario design - all of that exists for a reason.
And you have so much in your favor as it is! Why worry about that last 1%, figure out how to use the 99% of the game that you
do control to accomplish your objectives. Strangely, it seems that you very much accomplished your stated goals anyway - the player was scared at first, and later they rejoiced. Are some DMs never happy?
Oryan77 said:
Or maybe it's because he can't take a move action then a standard action and finish it off with a reasonable partial move action just because it's against the rules.
No, not just "because". I can't run to Wisconson and back on 1 round because of more than just the rules. Like I said above, if you reasonably think that an action is a partial action, then you can jam 15 partial actions into a single melee round because of time and space and because the rules purport to achieve something approaching a plausible quasi-reality.
It may be a case of special circumstances. If I'm a skilled fighter, I can move and draw my sword at the same time - the reasoning is that one action involves my hands/arms, and the other my legs, so I should be able to do both at the same time. Houserules like this, IME, are fine. In that case you're arguing from some foundation in reality.
Oryan77 said:
And I can't let them get away with it because they prefer to stick to the rules (well, they prefer that my NPC's stick to the rules...they wouldn't mind getting away with things if I let them...and if I can't do it, they can't do it

)
If your players want to play a game, then it's fundementally dishonest to change it into "railroad story hour" without their consent. You could always say "Hey guys, this whole rules/dice thing is getting in the way of me scaring you as much as I could. What-say we just put away the rulesbooks and I'll make up what happens and tell you about it?".
They could go for it. Or they could insist on the game, in which case if you want to be a DM then I guess it's about learning to work with the tools that you have. I think you underestimate yourself anyway, because AFAICT you're more successful than you think.