Now that I've tricked you into clicking this, I can be honest: This is about IP Proofing. I'm going to directly challenge the assumption that, over the course of 20 levels, you are not allowed to die once.
Everything I know about the IP Proofing argument is from reading handbooks and significant archived threads. If this argument has been brought up before, I severely apologize, since I've probably started a flame war. Here we go.
Let's start with a party of four 9th level characters (you'll see why in a bit). They have their expected WBL: 36k GP of items.
As DM, you've written a schedule of 14 encounters, centered on CR 9, with which you plan to up your players to level 10.
The probability gods frown on your players, and over the course of the first four encounters, each party member dies once. You now have a party of four 8th level characters. Per table 3-2 on pg 49 of the DMG, 50% of their encounters should be CR 8. Of the remaining 10 encounters on your 14 encounter level 9 to 10 schedule, only 10% of those encounters are going to be CR8. Therefore, if you do not recenter your encounters around CR8, as DM, you are not doing your job. This isn't coddling, this is following the rules.
But look at your level 8 party again. They started with 36k WBL. Let's say they put 5k worth of items at the pawn shop to pay for those Raise Deads. That leaves them with 31k in magic items, 4k more than an 8th level character should have, and I'm completely ignoring the treasure they got from those first four encounters they failed at life on.
Okay, so, you're a God among DMs, and determined not to coddle your players, and manage to find a way to plan your encounters centered on CR 8.1 or whatever. That still means they're going to play through 8 of those encounters to regain level 9. Looking at pg 54 of the DMG, "Behind the Curtains" on treasure, they're going to pull in a little more than 5k gp of treasure. What are they going to do with that 5k? Get the items they pawned to pay for Raise Dead out of hock.
They are now level 9 again, with their expected WBL, and get another shot at your CR 9 centered encounters, without having "fallen behind" at all.
If letting them pawn items 1 for 1 is DM coddling, then just up the example to 12th level characters, and they can flat out sell their items at the 2:1 ratio to pay for their Raise Dead spells, and still be overwealthed for 11th level characters... which is going to make replaying through the second half of 11th level a lot easier for them (unless you decide to calibrate the encounters some fraction of a CR), also netting them 50k gp of treasure. They use up 40k of that treasure replacing the items they sold for the Raise Dead spells, and still have 10k to gloat over. It gets worse at higher levels. All this player death means, as DM, at high levels, you're actually going to be sawing at the reins to keep your players from exploding with treasure... or they're going to be burning through consumables at an incredible rate. Expensive material component? I'll buy 12.
IP Proofing is still important. Your characters still need to be IP Proof to the point where they only die once every two and a half levels or so. (Once to fall back a level, then a half level to regain that level, then a full level to actually keep advancing instead of being stuck on a treadmill) However, the idea that you must win 250 times in a row is bunk, if you play by the rules in the DMG.
Since every guidebook I can find on IP Proofing has been rage-deleted because of the ensuing flame war, I have no idea how IP Proof you need to be for this to happen. And quite frankly, I am not up to the math. Help?
Of course, all this madness doesn't start until level 9 at the earliest, and level 12 at the latest. Until then, they would do well to have a patron who is willing to keep loaning them the Raise Deads they need until they are high enough level to pay it back. Is that DM coddling? Possibly. But it's also realistic. If I were a retired high level cleric (Those aging penalties can kill your adventuring career), I'd be raking in the dough simply by loan sharking low level adventurers, and squeezing the ones that make it to high level for ridiculous interest rates. Which, btw, is a GREAT way to "saw at the reins" for all the treasure your high level characters are going to be exploding with. Re-fluff as necessary. Benevolent father figure instead of loan shark, pious donation instead of paying back interest, whatever.
Again, I apologize if this has been brought up already. If it has, it needs to be added as an addendum somewhere in the handbooks section, since going through that is where I found all the flame wars about IP Proofing.
