So the party wants to fight a pit fiend...

[D3agle93]

My main gaming group is currently in a bit of a pickle. In the setting, the party has been actively trying to usurp a church of absolute evil gods that has taken over a post-apocalyptic Earth, and we have caused enough damage for some epic or near epic level officials to want us dead. It seems that they have called a pit fiend to their aide in dispatching us, though we are not sure if it is here to kill or just as a show of force.

The party right now is level 15, and our layout is a little bit fluid. Currently, we have my human lawful neutral swashbuckler / rogue / swordsage / avenger (lawful assassin) who is kinda an all-rounder. Our chaotic good (emphasis on chaotic) half elf favored soul who plays like a white mage meets Pokémon master via summon monster. A neutral good halfling rogue/swashbuckler with some swordsage who is death incarnate and also the only truly min-maxed character, a stereotypical neutral good TWF human fighter, and the DM PC, a mess of odd levels that grant him a fair blend of spell casting and martial skill, focusing on blasting lightning spells and channeling spells via duskblade. We may also have a neutral dread necromancer and a druid/warshaper, though they are not at all guaranteed. The rest of the party is chomping at the bit to fight this thing, while I feel like I'm the only one who understands how much of a threat it truly is. I believe that the purpose of the devil is not to kill us, but to soften us up so we are forced to run when the epic buggers come to destroy us.

What I'm looking for are any tips, tricks, plans, strategies, or general advice to deal with this threat.

[FocusWolf413]

As high ranking devils, Pit Fiends need to deal with almost constant assassination attempts. They'd have grown accustomed to people trying to kill them. They'd always have magical defenses up, protections against disjunction, and an empire's worth of magic items for protection. Remember, Pit Fiends are the commanders of the near infinite armies of Baator. It is an undeniable fact that they would use extensive expensive magic items to protect themselves. Let's not even get into their bodyguards.

Going further, Pit Fiends receive a constant stream of info about possible assassination attempts, military developments, and anything else that could possibly he of interest. Like dragons, devils have eyes and ears everywhere. E v e r y w h e r e. Devils are meticulous, paranoid, efficient, and they plan ten steps ahead. It would know of the party's plan ahead of time, and the party would die before they attacked.

Also, it is hunting the party. It's going to remain hidden and untraceable until you let your guard down, then BAM! It'll teleport in with its buddies, lay down a disjunction and its most brutal spells right off the bat, and come in for the kill.

Fighting a properly played pit fiend is like fighting a properly played ancient dragon: it happens when you're least prepared, and you die.

[Malroth]

Well it's not quite High enough level to simply Blasphemy you guys out of existance although with +1CL from an Ion stone it could do so to any lower level party members. It's Stat block seems to state it prefers to fight as a Blaster Gish but it does have High INT and CHA and has several methods of obtaining minions so it's likely to keep the party under survalence via incoporeal undead or Imps or Magic items and wait till a moment of vunerability, It's also likely to have +5 inherent modifiers to everything as well as an absolutely perfect custom set of magical items since it's had milennia to wish itself whatever it feels it needs to shore up its' weakness are.

[FocusWolf413]

Anything that's coming for you as part of a hit squad isn't going to fight fair. They're going to go in when you're weak, target one or two people (casters or your most dangerous people), teleport out, and hit you again the next day. You need to have (greater) anticipate teleport up at all times. Preferably on two people. You need to be buffed for a fight at all times.

If they don't try to kill you, the DM is pulling his punches, and that's never fun.

[D3agle93]

Thank you for the advice. I posted this about two minutes from passing out, so there were some minor details I missed. The party is currently working with a resistance group within a major metropolitan area. Think Mega City-1 from Dredd and you got the general idea. We have been making plans to evacuate a couple hundred people via underground tunnels. The day before we planned on going, our halfling saw the Pit fiend tear through a room full of civilians like a buffet. We learned its name, Stat block, and how it was summoned (greater planar ally) through a chain devil and hound archon summoned by the favored soul, and the others wanted to adjust the plans to factor in hunting it. In the end, we went ahead as originally planned, one thing led to another, and now we've got helicopters crashing into buildings and a pair of enlightened and sacred fists hunting us down.

The current plan for when the fiend inevitably finds us is to have the favored soul summon as many archon as she can to flood the area with magic circle against evil and hopefully distract it for a round or 2. Meanwhile, the casters will be trying to pin him with dimensional anchor while the non good party members engage him directly. This will probably not work out, but we have some homebrew systems in place that somewhat even the playing field. Any comments on this plan are appreciated.

[FocusWolf413]

The fight will not be on your terms. If the dm is trying to kill you, you'll be hit unawares.

They'll TP in invisible and buffed for combat.

Surprise round is a targeted greater dispel against your casters by the support and big bad. It'll take out your favored soul in the first round or two, and your arcane caster after that. It should target your divine guy alone or with one buddy, and have the mooks distract the arcane.

After that, it should probably TP out. It'll wait for however long, and then TP in and take one guy at a time.

It's going to use scry and die tactics. Don't let it. Keep up your anti scry buffs and your anti teleport defenses. That's the main thing. You need to see it coming.

Your first round should be reorganizing into a defensive posture, casting summons, and dropping your battlefield control. Fog, walls, magic circles, etc. This is the round to use your belts of battle. Have your melee drink whatever potions, activate your short term items, etc. Abuse the action economy.

Round two for the casters is casting greater dispel if they have buffs up. See if you can greater bestow curse the big guy targeting saves. Dimensional lock if you can. Melee should converge on him and defend the casters.

Round three is trying again to land another bestow curse, targeting actions if the first one worked. Cast banishment, holding a silver (and good aligned if you can) weapon for a bonus. Ask if an angel counts as something strongly aligned to boost it by the greater amount. It should at least boost it by 1. You'd be getting at least +2 total against its save. Melee keeps getting in the way, disrupting spells, and generally trying to kill the enemy.

Round four-end is more of the same.

Remember, you might not be able to win. In that case, survive. Teleport out if stuff goes sour. Do not let your arrogance lead the way.

[Hurnn]

If the pit fiend is really looking to kill it can invisibly teleport in buffed like crazy, Open the surprise round with a blasphemy then a quickened fireball, wash rinse repeat. "If" you had any evil party members they could try and distract him long enough for the rest to get back in the fight but at will blasphemy is just brutal.

[Jowgen]

You seem to have a very political game going, so if your DM runs Baator as described in FCII, maybe you'd be better off meeting the Pit Fiend in a more political manner. There are bound to be dozens of other Pit Fiends or similar down in Baator who would love a chance to kill/undermine that particular one you're dealing with. Could be someone serving another archduke, could be a colleague working for the same one, there really shouldn't be any shortage. Baator is always eager to make deals with mortals as to switch their alignments or right-out gain property rights to their souls, so it's not like getting in touch should be hard.

I suggest starting by trying to find out whom the Pit Fiend is subservient to down in the Nine Hells. Since you know quite a bit about it, you might be able to get off a Legend Lore in time, but that's just one method.

[sleepyphoenixx]

Get a Binding weapon or a way to cast Dimensional Anchor. Few things are more annoying than the big bad escaping when you have him on the ropes.
Get (Greater) Anticipate Teleportation to be prepared when it comes, then have everyone ready actions to attack it when it appears.
As others have mentioned, keep up those divination blockers (assuming your DM plays fair. If he doesn't it might not matter).

Once you engage it and get its teleportation blocked you can fight it relatively normally. Don't stay in full-attack range, because that claw/claw/wing/wing/bite/tail routine will mess you up. At least it doesn't have True Seeing, so miss chances work.
Keep in mind that it has Greater Dispel as a SLA. Since you can't counterspell it some normal defenses against dispel might not work (Ring of Counterspelling, Ring of Spell Battle), but a Spellblade keyed to Greater Dispel will.

The Blasphemy can be countered with Greater Spell Immunity, but you'll probably have to get a scroll unless your favored soul has it. Spell Resistance in general can help but it's likely to fail half the time and hurt more than it helps. The other option is to spread out, leaving more than 80ft between players, but that only works if you have the room to do it.
Silence also blocks it (since it's [Sonic], but your casters need to be prepared for it or it's going to cripple them. Getting a good melee PC silenced and in front of it might work, if he can lock it down, but keep the full attack in mind. Even then it still has that Greater Dispel SLA, so it's unlikely to buy you more than a round or two. I suggest a Ring of Silent Spells (MIC) as a cheap option to reapply, and it only costs you a swift action to use it.

Other than that you're going to want immunity to mind-affecting (for the Mass Hold Monster and Power Word:Stun), Greater Dispel Magic with a boosted CL (to get rid of Unholy Aura) and fire resistance (Meteor Swarm and quickened Fireball).
Casters should also look for a way to pierce its SR 32, while melee has to content with AC 40 and the danger of staying in full attack range. Piercing the regeneration shouldn't be a problem at your level.

As you can see, it takes a bit of preparation, and that's all disregarding any minions or magic items the Pit Fiend might have. But then it is a major devil, so you shouldn't expect an easy fight.

[Seward]

The only real advantage you have is action economy.

Don't let him take it away from you. Fight in a silence field to block the Blasphemy. Be fire resistant or immune. Have your best, most reliable ranged hitter readying actions to interrupt spell-like abilities. This is vital, it prevents teleport, summons and greater dispels. It isn't likely to stop any quickened effects but it helps. Force it into a strict melee fight and your odds increase greatly, especially if your close in fighters are buffed properly (at minimum fire resistance and something like stoneskin, plus every AC enhancer and miss-chance inducer you can pile on).

Obviously you also need to somehow isolate the pit fiend, because with minions, the action economy shifts to the other side and you are all dead. So in addition to the anti-blasphemy silence and disruption of any spell-like abilities, you'll need something to wall off any minions in the area. At level 15 you are high enough to do scry & die tactics of your own. Choosing a minion to scry on is always better than challenging the big-guy, preferably a minion who lacks spellcraft.

[D3agle93]

The major issue I forsee my party running into is our spellcaster's lack of versatility. We have the favored soul who specializes in summoning and healing, the duskblade/wizard/bard who is built for blasting, and the dread necromancer who is, well, a necromancer. Our setup is stacked for killing everything as quick as possible, not really for a prolonged fight. We have a homebrew system we're using that grants us a temporary power up that might help, but if the DM plays the Fiend right it won't matter. On top of all that, given the nature of the campaign, we are extremely light on magic items. We have Stat gear, our weapons and that's about it. The worst part of it is right now, we have almost nothing that can actually harm it. The favored soul has a few good spells but that's it. No silver weapons yet, though the favored soul will soon be able to smith some.

[Th3N3xtGuy]

May I suggest something to create a complete anti magic zone. Allowing only brute force to succeed which Group vs Pit Fiend it could be in your favor.

[D3agle93]

A reliable means to use Anti-magic anything has been on my character's wishlist for the past 10 levels. In the setting, the only people with any magic worth using are us and the villians. The DM is not a fan of anti-magic. His specialty is melee casters with tons of buffs and blasting. An AMF leaves 90% of his stuff near useless and forces him to do a ton of number work removing buffs, an agravation he tries to avoid.