Help with campaign!

[Geopol4r]

So, I am running a campaign and I need help with the big fight. I am thinking of a psionic ilithid. How should I build it?

[Geopol4r]

The adventure will be midlevel and I want it to be a challenge.

[Samwich]

My best advice would be to give the monster a good body of minions. If it's psionic, it could have dominated a wide variety of different creatures that it uses to fight in it's stead.

[SunderedWorldDM]

When you say "the big fight", does this mean the end of their first dungeon? The end of that campaign or that chapter of the story? What are you looking to get out of this fight? Will this Mind Flayer be a villain that will have menaced them before or will they just be a big dungeon boss? If you could give us more insight into your thought process, that would really help us realize your vision!

[Kaptin Keen]

I wouldn't worry too much about build, or even challenge - as such. But that maybe just me. I'm way more interested in evocative narrative than crunchy builds. I'd focus on why he's a villain - what he wants to achieve, and how he wants to achieve it. If he's a mindflayer, and already big on slaves and domination, maybe he's a thrallherd? He may not be high enough level to be a really good thrallherd, but .. well, I guess he might, if the players are around level 8-ish?

I generally build mind flayers as flesh crafters. So I allow them to build all manner of homebrew monstrous abomination that I dream up.

[Geopol4r]

By "big fight", this is as far as I can plan.

And flesh crafters?

Though I do like the thrall herd idea.

I already have him capturing villagers to send with magic items to kill the party.

[Thinker]

The setting of your big fight matters at least as much as the opponent. An area with murder holes, rough terrain, and cover for the enemies will be much harder than an empty, small room. Consider what advantages your illithid will have on home turf and let the players try to move the fight. Play up the monster's motivation and personality. Is he prideful? Maybe he can be goaded to fight without his minions. Is he craven? Maybe he will try to flee if it looks like the party is getting too close, allowing them to trap and capture him. Is he careful? Maybe the players can simply imprison him in his own lair if he's unwilling to come out. The monster's abilities are largely secondary, but should play well with whatever setting you have in mind.

[King of Nowhere]

you should at least specify the system you are playing.
then the party setup and optimization level is also very important.
we need many more informations to be able to come up with useful answers

Also, please avoid multiposting. if you think of something else you want to add after you sent the post, you can use the "edit" button.

[SunderedWorldDM]

So with an Illithid, I typically think of hypnosis and mind control as common tactics, and the villagers that they're sending after the party are probably implanted with tadpoles or intellect devourers. Consider using the devourers, as when the villager dies you have the little brain scampering about and causing trouble for a couple more rounds. In big fights, the way 5e works, it's a lot more useful to think in terms of spreading out across many forces than by building one big central monster, as hitting the players in the action economy hurts a lot more than hitting them in the hit points.

One technique that I picked up from Hankerin Fernale of Runehammer is the TTT method. Timer, threat, treat. Your monsters are going to be your threat. Your illithid, your villagers with the devourers, your stiched-together abominations, whatever you decide is cool. Your treat is something that the players can use to their advantage on the battlefield. For example, maybe there's a pillar unstable enough to be knocked down on top of enemies and deal a lot of damage. Perhaps in the ribcage of a fallen adventurer lying to the side is their Holy Avenger and a potion of healing to aid the players. Any sort of thing that would give them a little boon.

Your timer is something really fun. Typically, your timer dice would be a d4, though for a big fight I would recommend instead rolling a d4+2 and displaying the result on a d6. You roll this when the players roll initiative. Every round on your turn, you tick the timer down by one. For example, if you rolled a total of 5, on your first round you would move it to 4. When the timer would reach 0, something major and bad happens. For example, perhaps massive clouds of poison gas flood the room, dealing lots of damage to the PCs while leaving the enemies unhindered. Maybe the villain's ritual is complete, and they become powerful enough to brutally harm the PCs and flee alive and more powerful than ever. You'll know what happens at the end of a timer dice from the context of the battle and how high you want the stakes to be. Maybe when the timer dice runs out, everybody dies, monster and PC alike, as the dungeon is swallowed into the void!

So. Use TTT, use a lot of monsters instead of thinking about the one big boss type, think about how terrain affects the battle and make the landscape interesting, use minions, and you'll be well on your way to making a memorable and pulse-pounding boss battle.

Also, 'flesh-crafters' means that this person likes to stitch things together in strange configurations, like Dr. Frankenstein. This sort of behavior is often attributed to Mind Flayers, and a couple of monsters that are shambling heaps of stitched-together flesh would really put the fear of DM in your players.

[Geopol4r]

Oh, cool. Also, I am using 3.5. I love the ttt idea, and I will take this all into planning.

[JNAProductions]

Just an FYI, we have a specific subforum (http://www.giantitp.com/forums/forumdisplay.php?59-D-amp-D-3e-3-5e-d20) for D&D 3.0, 3.5, and Pathfinder.

You don't need to repost there, just report your first post and a moderator can move this thread.