@ Quickleaf: good stuff there. The entire cliche thing is besides the point in this dicussion, really. The scene you describe does seem cliche, but your narration makes it look cool nonetheless.
So "good use of cliche?" Heh, I'll take it.
I find it too bad that such a great RP moment would raise eyebrows from your players with regards to their incapacity at healing the NPC from a purely mechanical standpoint. This is a moment where they should dive into the scene IMHO.
To their credit they really did. The only exception was the other very experienced ex-DM player of the bard. And despite him being annoyed and us having a 5 minute headbutt, he rolled with it well and even created a suitable sardonic epitaph for the NPC.
And by the way: are they aware that NPCs don't necessarily have healing surges in 4E?
Really? I thought the DMG made it clear that NPCs have 1 healing surge per tier. But that makes sense to me.
Also, doesn't it strike you as odd that you arbitrarily ruling that the Lord has been attacked and badly injured by the enemy is fine (you're not rolling each and every battle between NPCs that occurs in your game world, are you?) but you not rolling for his death saving throws is frowned upon? Why is that? Once the PCs enter a room, the rules for NPCs should change? But as soon as they go out for a breather, he can die without questions being asked?
Heh. That's my perspective too. But it's clear many players feel the opposite: that if the PCs are present then the rules should apply consistently and without exception (er...unless the rules themselves are the exception). I wonder if this became more prominent during 3e when PCs and NPCs/monsters had the same mechanics? That would explain some of the disconnect I had with the bard player...
[MENTION=20323]Quickleaf[/MENTION], I hadn't realised it was a 4e game. To my mind, that makes what you did all the more legitimate within the rules.
Really? How so?
Like I posted upthread, I've done exactly the same sort of thing - had the PCs rescue NPCs who are maimed, blinded etc from combat with hobgoblins, and who are therefore beyond the help of a healing word or similar spell (again, how can we tell that? because those spells only heal hit points, which recover after a night's rest, and therefore can't on their own represent anything all that debilitating).
You too with the hobgoblins inflicting incurable wounds, huh? Must be something they feed their babies.
As I said in my post just above yours, the only mechanics-related issue I can see here is one of jarring with the players' expectations if the nature of hit point loss and hit-point based healing hasn't been thought through - that is, if they haven't noticed that the action resolution mechanics used to handle combat don't encompass the full possible range of combat-related injuries that are possible in the fiction.
I know this debate has been around since D&D, but when I played 1e and 2e it was clear that attacks were only in part physical damage (can't remember if it was just a play style thing or if it was explicitly written in books). I don't know if that was the case so much in 3e since my experience was limited. In 4e it's clearly called out that hit points are an expression of more than just physical wounds.
The GMing style issue seems to me to be this: as you describe the scene, you wanted the dying lord to be colour (and Crazy Jerome already diagnosed it this way quite a bit upthread), and you liked the colour of that better than you did him already being dead. The question for your players was - is this colour, or is this a challenge we can engage with? You've exerted some GM force to establish beyond doub that it's just colour. And you haven't been coy about it (ie you stated that you didn't roll the death save). There was no illusionism here, just upfront force.
Yeah [MENTION=54877]Crazy Jerome[/MENTION] did a good job of explaining how "color or challenge?" can be problematic.
I've been interested in the advice about creative ways to interface with the rules and have an NPC be un-healable (e.g. the magic poison). To me that seems more illusionismary

Is this magic poison a critical plot point? Or is it the DM's device so we just can't heal him...unless we figure a way around it? However, it appears there's plenty of folks who consider that a better way of handling this scenario than "Remember when you decided to go through that portal instead of to the keep? Yes I'm framing a scene here."
Whether this is objectionable railroading, or just reasonably hard scene framing, is not something anyone else posting here can work out in the abstract. It's all about whether your players are into that sort of hard scene framing, or not.
Every time I've introduced a truly open-ended situation with a plurality of options, they've drifted off, debated endlessly about what to do, caved in to the strongest voice, or began making knowledge skill checks with piercing looks my way....

What can I say? Hard scene framing works well with this group, and I've become comfortable (too comfortable maybe) being up front about it.