I'm not sure exactly what the problem is and I have, in subtle and not so subtle ways, tried to encourage him but all to no avail. It's not that he's not intelligent, in fact I'm almost positive he's the most intelligent of our group, and I don't think it's because he's unimaginative, he just doesn't seem to want to DO anything.
He may be shy. Is he normally shy in life? Is the game or the group new? I was shy with my latest real life group, I took me a whole three sessions (and some beverages) to warm up to the point where I was contributing at a level on par with the other players.
One example is when he was held in a web and couldn't get out. He could've cast spells or fire his bow at enemies but he did nothing. Playing a bard character meant that he could've at least sung to help his comrades but all he did was struggle fruitlessly against the web for over ten rounds!
I know, you are probably thinking there is an echo in here by now, but are you sure he knows what he is doing? He might even have an In Character reason for doing what he did, but I’m getting the sense that such is a long shot.
Another example was when it was patently obvious that there was a secret door in a wall but nobody could find the trigger mechanism (the Search DC was too high) and if he'd just have inspired someone and thus given them a +2 bonus, the players would've found a 10,000gp diamond! It's SOOO frustrating to see this kind of thing happen and not be able to just shout, "DO SOMETHING!"
Did you state what the DC was? If not how is he supposed to know it is a +2 Bonus difference, it just as easily have required an extra +3 or +20 for all he knows. It might also be an In Character thing, or he may be looking at the song from a different angle. Many can see a song giving you courage helping you fight longer and harder, but when I loose my keys the first thought that pops into my head is not, “I should put some inspiring music on.”
Of course if this is meta then it falls back on not knowing everything about his character and what he can do, if it is in Character then you can simply ask him why. But either way I can see reasons for not singing.
Also, how did he know there was a 10,000gp diamond behind the door? If it was so obvious to locate couldn’t it be a trap? Heck maybe it could be treasure in his mind but only a couple copper pieces and not worth wasting a song. If such is the case he sure wouldn’t want to help spring it, now this line of thought could be meta or in game, but if this is what he was thinking he probably needs to work on communicating with the group
What can I do to inspire him? Like I said, I don't think it's because he's stupid or unimaginative, but he just doesn't seem to get involved very much. I've asked if he enjoys playing and if he's bored and he said he does and he isn't but that's about the only thing I can think of that it could be.
Some people like to hang back wither they are shy or not. You could always see if he wants to try a character type that would possibly work better with his play type, how about a Healing Focused Cleric? He gets to basically sit back heal, and still have the fun of playing and contributing to the group.
There are defiantly other reasons then boredom, but the only way you are gonna figure out exactly why he doesn’t play like you want him to is to sit down and talk with the guy, but depending on how you both handle it you might wind up turning him into the player you always wanted, or have him leave the group and possibly ruin a friendship. (Assuming it is there in the first place, but considering you are playing I assume something exsists.)
I really don't see how giving the players something when they don't earn it helps anyone. I'm of the opinion that the characters are adventuring in a world where they can change things, not that they're adventuring in a world that changes for them.
And they did take 20. The DC was 30. The highest Search skill a party member had was +8.
Then why are you lamenting over the loss of the gem? They ran across something, they missed the DC to get the result they probably most wanted and they moved on. Tell me, did anyone mention that fact that his singing could have helped? An In Character quip like, “How ‘bout some music to help us search?” or even a Out of Character comment would have worked.
Again this falls back to him not knowing the rules like the back of his hand, also as was mentioned if the Aid Other action was viable and would have gotten the prize why aren’t you lamenting about that as well?
