Help me come up with some refreshing / challenging encounters?

[thechosen2nd]

Hey everyone! I recently started running a campaign based on a sort of "tower defense" theme. The party is under attack by a hobgoblin horde, and must defend a stronghold against the hobgoblin army and their minions, which will attack in increasingly difficult waves as the game progresses. (I also have much bigger plans in terms of overarching plot-lines, the enemy head honcho, and the war in general, but I don't want to post those here in case one of my players stumbles upon this thread.)

The party is level 6 to start, with a 20 point buy, which means I have to throw a lot of hobgoblins at them to make an encounter challenging, but that was basically the plan all along. However, I'm worried that just chopping down hobgoblins day in and day out will get boring after a while... Plus, this is really playing to the advantage of the ranger in the group, who of course stacked his favored enemy bonus against goblinoids, and right now is looking a bit overpowered. (If you're curious, the other PCs are a barbarian, fighter, and cleric.)

So what I need YOUR help with is coming up with some variety. What sort of creatures might find themselves in a hobgoblin army? Maybe slaves forced to fight, or malicious beings there on their own accord? I would also love some ideas for "bosses." (I've already got plans to send a couple ogres barreling through the ranks at some point, but I need more ideas... the bigger and badder the better.)

Any thoughts on templates I might use? Heroic levels and feats that will be strong against my overpowered archer PC? Any other advice/suggestions/ideas in general? I would love to hear it.

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TL;DR: What nefarious schemes might an extremely influential and powerful hobgoblin warlord hell-bent on conquest throw at a bunch of PC's other than just a ton of goblinoids?

[rangerjeff]

A few notions off the top of my head. Keep it episodic.

Day 1 the assault! Which is, of course, repelled, though the tower is now under siege. Perhaps first the battle is with troops outside the tower, trying to defend the farmland, etc, and eventually a withdraw to the tower.

Day 2 or at night or something, renewed push from outside, trying to go over the walls, repelled on the walls in dramatic fashion with the defeat of a warleader of some sort.

Another attempt to get inside, hobgoblins tunnel, surprise attack from somewhere within the keep. Ooo! Save the women and children in the sanctuary! Don't let them spoil our stores of food and water! Block up the tunnel before more get through! And mind the walls, because while you're distracted they'll try to get over them again.

Then let the siege drag out. Have some politicking/roleplaying to keep everybody together inside, as some may want to backstab others and offer the lord of the tower's head to the hobgoblins in hopes of being allowed to survive.

Maybe the hobgoblins infect the tower with a plague, and the cure is an herb outside the tower, so an escape and then return to the tower is required.

Or, an escape and return with reinforcements to break the siege.

Perhaps it's part of a greater invasion and there are no reinforcements to be found! And likewise the hobgoblin leader is shamed that he hasn't taken the tower yet himself and refuses to call for any help from other hobgoblin divisions.

A daring raid on the hobgoblin encampment to take out their new secret weapon!

Perhaps finally when things are looking bleakest (supplies running out, numbers dwindling) a desperate quest to find unexpected help, perhaps legendary fey in a relatively nearby wood, or an artifact from a legendary ruin which allows command of elementals or undead or something.

My point is, simply throwing monsters of increasing difficulty at the walls, yeah, that'll get boring. Think about what makes a siege tense, all the unexpected things that can happen. Change it up. Keep it episodic, though some grand scenarios/modules stretching out over 3 sessions is okay, too.

[rangerjeff]

Oh, and a shaman or two with wind wall will shut your archer down.

[Mark Hoover]

give them a survivor they take in; let this NPC gain their trust, even going so far as helping them defend the walls. Then when they're not looking trojan horse them with the NPC

Sapping is fun

Germ warfare with dead animals and vials of the Contagion spell hurled over the ramparts

Finally summoning. When the hobgoblin warlord gets desperate maybe a patron devil is called up to lead a final charge...

[Wind Chime]

Fun with ladders and siege engines would be on the list. Infiltrating the Hob Goblin camp could be fun. I would also make them deal with goblin sappers so they could fight in the half finished claustrophobic dark tunnels under the fortification dug by the goblins to sap the strength of the walls.

[osinbar49]

Negotiations with an outside group for aid in defeating the threat.

I also believe that understanding the motivations of both the hobgoblin invaders and the PC defenders will cue more encounters.

[darkwarriorkarg]

Do the hobs have any spellcasters or alchemists?

magic warfare:
There's an alchemist discovery for seige weapons...
Earth elementals
Is there a weak point in the defense? You can always strap a barrel of gunpowerder to one or more goblin slaves that charge forward.
Water elementals in the water supply

Psychological
Villagers in catapults to demoralize the defenders. Living (before launch) preferred.

Bosses
1 seige leader: (Cavalier 9/Mammoth Rider 1) with a huge wolf.

1 Spiritual leader: Oracle(Battle) 8, Curse: Legalistic or Bard(Thundercaller)

1 2nd in command: cavalier(7) with a large wolf.

1 Mad Bomber (Alchemist 6 or 7)