I could use some help planning a large-scale encounter.

Setting:
I'm running a game where there are a number of things going on in the galaxy at the same time (The Empire has research divisions undertaking nefarious projects, a criminal syndicate are after the PCs, A force sensitive nemesis or two are still at large, The rebels are operating both as terrorists and heroes in their different cells) and one thing the party did was to seriously get under the skin of an inquisitor by rescuing a handful of force-sensitives from his secret facility. This is all set in the period around Episode V.

The party have a mentor - a slightly dark side 'The ends justify the means' kinda guy - who they have slowly come to understand and of whom they are now slightly less judgmental, and are living with him and a small town of non-force-sensitive NPCs (mostly ex-miners) on a fairly secluded planet. This planet is largely forest, but has two very important features:

1. It's very rich in metals and minerals in its more mountainous regions.
2. There are force-sensitive creatures (like Vornskrs ) in the forest, making the planet a nightmare for any mining corporation who sets their sights on it.

The vornskrs make it hard for the Inquisitors to sense/seek the party on the planet, and the party keep the vornskrs from venturing too close to the settlement. A nice symbiotic relationship that benefits everyone (except the vornskrs). Over the time the party have spent here, they've made some friends and become very attached to the people who live there.

The Encounter:
The Empire - being the vast and ever expanding war machine that it is - will eventually expend an untold sum of resources hunting the party and find them on their haven, and when it does it will turn up with some heavy military equipment and one very hostile inquisitor who wants back what they stole (plus a side of revenge)

My current ideas for the scenario are that they may have brought walkers, will have an Interdictor in orbit somewhere, and the ground forces will be highly coordinated and specialized in supporting the Inquisitors. Beside that, I'm at largely at a loss. What I want to achieve is the following:

• A way for the party to realize the Imps are coming and maybe get an early warning.
• A clear moment when the party will realize they face overwhelming odds.
• A large-scale combat encounter with lots going on
• Encounters around the settlement where people will need rescuing.

Now, I've never done an encounter this big, so I'd love to hear any ideas you can throw at me. (happy to answer any questions about the settlement or wider plot if needed)

Edit 1: Forgot to mention. The force sensitives they rescued are children.

Quick pre-coffee thoughts.

13 hours ago, SufficientlyAdvancedMoronics said:

• A way for the party to realize the Imps are coming and maybe get an early warning.

Well any attack should send scouts first. This could be a Gozanti that sends a couple recon TIEs over the colony in a flyby, before the Interdictor arrives in-system. Or the Interdictor is already in orbit (unknown to players?), but drops a few Scoutroopers for a recon. Or the classic ESB use of an Imperial probe droid that arrives at the edge of the colony.

13 hours ago, SufficientlyAdvancedMoronics said:

• A clear moment when the party will realize they face overwhelming odds.
• A large-scale combat encounter with lots going on

Possibly have it come in stages that are increasingly difficult. This will cause the dread to come slower and thus more dramatic. It will also allow you to not accidentally overwhelm them. So, first the scouts come which are possibly easily defeated. Then shuttles are seen landing in the distance. The initial attack comes as just Stormtroopers. When this is defended, TIE bombers are sent over the colony causing random damage. Then large AT-AT shuttles begin landing in the distance (no massive orbital bombardment due to the Inquisitor wishing for direct revenge?). More Stormtroopers show up in this larger second wave with the Inquisitor leading them....as the ground begins to shake from multiple AT-ATs headed towards the colony. That should be enough to send the players packing?

Are you hoping the PCs flee by ship, or just retreat to hide into the forest for a future hide and seek campaign against the Imperials? Is that why you brought the Interdictor? To keep them on planet? If so, the players need to find out it's up there somehow - they actually see it in low orbit, and/or sensors pick up the anti-hyperspace field, and/or they intercept Imperial communications such as, "The Interdictor's field is online sir, the scum won't be able to flee now".

The mentor could exclaim that its too much for them, yell for the PCs and miners to retreat into the forest to hide, which leads to future guerilla warfare sessions?

13 hours ago, SufficientlyAdvancedMoronics said:

• Encounters around the settlement where people will need rescuing.

• Near the onset, Scoutroopers capture a miner for interrogation and drag him off into the forest.
• TIE bombing caused a building to collapse on some people who need pulled out or medical help, all while Stormtroopers begin assaulting the colony.
• A defense line of miners on one side of the colony reports over comms that they are about to get over-run by Stormtroopers and need immediate assistance. Perhaps comms cuts out with, ".....and they have an Inquis"
• After a possible retreat into the forest, a few stragglers still in the colony call out for help as the colony is getting over-run and the AT-ATs heads are finally seen over the tree tops headed their way.

46 minutes ago, Sturn said:

Are you hoping the PCs flee by ship, or just retreat to hide into the forest for a future hide and seek campaign against the Imperials? Is that why you brought the Interdictor? To keep them on planet?

Just to make escape more difficult. I don't want them to just jump to hyperspace and get away - I want them to either come up with a clever solution or resign themselves to having to fight their way off-world. Their pilot could save the day and run the blockade, or they could get sneaky and try to stow away on an imperial shuttle to disable the interdiction field from inside.

58 minutes ago, Sturn said:

The mentor could exclaim that its too much for them, yell for the PCs and miners to retreat into the forest to hide, which leads to future guerrilla warfare sessions?

That's a nice idea and one I hadn't considered. We've generally established that the forest is super dangerous, even for force-users. If they go down this route it could be really fun though. I'll be sure to keep it on the table as an option.

1 hour ago, Sturn said:

Possibly have it come in stages that are increasingly difficult. This will cause the dread to come slower and thus more dramatic. It will also allow you to not accidentally overwhelm them

I like that. It will give them time to take stock of the situation and attempt to prepare too.

1 hour ago, Sturn said:

Perhaps comms cuts out with, ".....and they have an Inquis"

I don't think inquisitors would be common knowledge, even here. I don't think the party have actually ever heard the term either, so it may not mean anything to them. I do like the idea of someone on the comms being terrified because the invaders are being lead by something they don't understand, and then followed by the sounds of a painful death.

1 hour ago, Sturn said:

When this is defended, TIE bombers are sent over the colony causing random damage

That sounds fun, but instead of random damage, I may get them using incendiaries - some kind of Space-Napalm - and setting the edged of the settlement ablaze to make escape that much harder. I like making sure the bad guys do bad things with purpose.

Really great thoughts, thanks.

By random damage I didn't mean rolling such. Just what you meant, stuff being destroyed about the colony, set ablaze, etc.

I had thought possibly they wouldn't know about the inquisitor, wasn't sure. That makes sense. That can be replaced with whatever a miner might yell over comms when first seeing one. "....and there's some person, some....thing leading them, is that a lights..." Or some such?

2 hours ago, SufficientlyAdvancedMoronics said:

I may get them using incendiaries - some kind of Space-Napalm - and setting the edged of the settlement ablaze to make escape that much harder. I like making sure the bad guys do bad things with purpose.

Having a miner run screaming by into the darkness alit with blue space-napalm may do the job. 😁

2 hours ago, SufficientlyAdvancedMoronics said:

I don't think inquisitors would be common knowledge, even here. I don't think the party have actually ever heard the term either, so it may not mean anything to them. I do like the idea of someone on the comms being terrified because the invaders are being lead by something they don't understand, and then followed by the sounds of a painful death.

Make it "They have some kind of Jedi..." followed by choking noises.

If the Settlement has Hyperspace Comms, jam them. Bring Star Destroyers, Have one with an identifying mark enter low orbit. Set up a ground side firebase in the center of town. Broad cast the Inquisitors treats over a P.A. system. Leave holes in security that the PC can take advantage of, like sewers.