Help me build the final fight of the adventure!

[ravenheart]

I just realized I won't have that much time to prepare for the game I'm running this Saturday and since it's supposedly the final fight/encounter of the adventure, I thought I'd give a shout out here on the forum for some assistance in building a truly magnificent finale for my players!


The party is level 6 and consists of 6 players + 1 CC. The target XP I'm thinking about using is somewhere between 2800 - 3500 XP (no unspent dailies, a few surges, all have action points). This could be bumped as far as 4200 if one uses waves and allows for a milestone refresh mid-encounter.

A basic recap of the last session:
- Just moments ago, the party successfully retrieved the Crystal Rose (TM, =MacGuffin) from the Sunken Garden (TM) in the Lost Valley (TM).
- In the process the Sunken Garden (TM) collapsed, forcing the party to hastily flee to the shore of the Lost Valley (TM).
- As they try to catch their breath, they are ambushed by the BBEG and his troops who are also in search of the Crstal Rose (TM).

The encounter area is the beach of a shallow lake in a small valley in the middle of nowhere. Temperate vegetation and cliffs are abundant.

The BBEG is a customized elite halfing prowler with a dash of assassin sprinkled in. He is relying on a great deal of melee mooks to protect him.
A bunch of archers/sharpshooters are sure to accompany him, perhaps hanging back on cliff somewhere. The mooks should be humanoid, but not necessarily halflings.

The party consists of:
A Half-elf Bravura Warlord (charge & heal, highest AC, good defenses)
An Eladrin Illusionist Wizard (slight powergamer, decent melee, GotG and Sleep)
An Elven Hunter Ranger (tactical skirmisher, tertiary healer, mobility)
A Genasi Brutal Rogue (melee focused, high DPR, utility)
A Human Hybrid Swordmage/Infernalock (flexible, hippogriff mount, catch-22)
A Warforged Hybrid Battlemind/Warden (multimarker, durable, semi-controllery)

Now, the premiss of the fight is that the BBEG tries to capture the Crystal Rose (TM) and rid himself of the PCs. He could try to bargain with the PCs first, but has no intention of keeping his promises (the PCs are to dangerous to be left alive). The PCs have good reason to mistrust the BBEG (they thought he was an ally) and might try to take him alive so that he could face justice. If things start to look hairy for the BBEG and his troops, he'll retreat hastily (if possible).

So... now I spent a whole lot of time writing this post, but this is honestly the easy part in my mind. My brain constantly switches itself off as soon as I try to shape this into a coherent encounter. That's why I need your help, ENWorlders! Please, help me make this awesome!

tl;dr - check the bolded parts, help me build an encounter based on that!

EDIT: Almost forgot - I use Gaming Paper! Just FYI.

 

[RangerWickett]

Well when I want an awesome fight, I usually go for a combination of:

1. dynamic terrain, to encourage movement
2. shifting circumstances, so that tactics shift
3. enemies who require some ingenuity to take out

#1 is hard to do on a lakeside beach, but if you want something to keep people moving, maybe something comes out of the lake. Like, the sunken garden has seaweed or something that grows out from the water in tendrils, changing the battlefield round by round -- adding cover and difficult terrain. Maybe it's thorny seaweed.

#2 . . . what does the Macguffin do? It's fun to use artifacts. When I had my modern d20 PCs find the Holy Grail, it charged as blood was shed, and then would pulse, healing anyone nearby it. Maybe have the crystal rose charge over the turns, then do something. It gives the fight some tension, to see if the PCs can take advantage of it.

#3? Not sure. Gotta go. Good luck.

 

[Lord Zardoz]

If you want to encourage movement, all you need to do is create a reason to justify an arbitrary number of squares as dangerous to be in. To that end, I must ask you how much ranged backup your BBEG will have?

I would suggest creating a volley attack action which is the result of the opponents lofting a large number of missile weapons into a given area rather then going for individual targeting. That zone can then be written up as having the following effect:

Bob the Halfling Prowler

Area Bombardment: Free / Special.
Zone, Area 3, +3 vs Reflex. Hit: 1d8+3 damage; Miss, Half Damage.
Area Bombardment requires at least 4 ranged attacks to target the same area. Each attacker beyond the 4th adds +2 damage and +1 to attack.
An attack is made on any creature entering or starting their turn in the zone.
Adding to the bombardment is a Standard action.

Minor Action: Direct Bombardment:
Bob can shift the targeted location of the Bombardment as a minor action.

So if you have 12 minion slingers as backup for our friend bob, you are going to be attacking for 1d8+3+16, at +11 vs Reflex damage to anyone within the defined attack area. It adds a huge incentive to target the minions making the attack, and the ability to reposition the zone can force the players to move.

END COMMUNICATION