National Conquest

[JellyMuffins]

Long story short, the party very recently began an evil but holy crusade of conquest.

I'm looking for ideas for tactical shenanigans as we take our fledgeling army and destroy our enemies.

The army currently stands at:

50 magical spiders (stats unknown)

35 lvl 13 sorcerers (specific stats and spells unknown, but surely flexible)

and probably 100 commoners in the process of training.

Enemy armies are likely to be about 250 - 750 strong, quality unknown. At least one young-ish dragon is in play for one of the opposing nations. So you have a sense of scope.

I'm hoping to cover bases I haven't thought of in taking the holy crusade across the land.

[Gwendol]

Without any intel on the opposition, or even the strengths of your own army I find it hard to give any meaningful advice. Could you at least give us the party set-up and what color the opposing dragon is?

[Heartspan]

Use your army as a distraction and take your party up to assassinate thedragon

[Mrmox42]

Let the commoners act only as rear-area guards, decoys and, possibly, cannon fodder. The sorcerors could act as hit and run commandoes, whittling down the strength of the enemy, while the characters do the really dangerous stuff, such as poisoning the wells, burning supplies, killing enemy leaders and, indeed, slaying the dragon, while everybody else is fighting of the commandoing sorcerers and the decoying commoners. Should be fun.
Remember to give the commoners a couple of leaders, of which one is young and impetous and eager for action, while the other is too cautious.
and let there be some really strange types among the sorcerers. Can they trust them all?

[Balyano]

I don't know how many enemy nations you're dealing with or their names, so I'll use letters.
Dress some of your soldiers up like they belong to one of the nations, we'll call it Kingdom A.
Raid a little into one of it's neighbors, Kingdom B.
Force a few small villages from Kingdom B to pack up and colonize some out of the way place in Kingdom B, near the border.
Draft some of those commoners into your military, but make them think it's their own kings military they are joining.
Have them use poor disguises, to look like Kingdom A soldiers dressed as Kingdom B soldiers and have them raid Kingdom C's borderlands.
If they haven't started killing each other yet, have some of your people go into Kingdom B and start fighting your own conscripted Kingdom A forces.
Soon they will begin encouraging the common people of Kingdom B to take back their land from the invaders.
If need be get your militias of people that don't realize they work for you to commit a few atrocities in the neighboring nations to escalate things.

If all goes well Kingdom B will invade Kingdom A or vice versa, thinking that the other really is attacking them and Kingdom C may get involved and fight one of the two.
Once they weaken themselves enough you should ride in with your full force and put an end to the war.
Kill the dragon or make friends with it.
Make sure to bring food, blankets, medicine, and beer.
Give it away freely to the suffering common folk.
Use some propaganda to convince the common people that all of this was due to the greed of the ruling noble houses.
They need leaders that look out for them, leaders like you.

[Heartspan]

^THAT, my friends,is how you get **** done!

[Celcey]

I think we need more information about your party composition as well as the kingdoms you're trying to take over. For example, if Kingdom A has a tyrannical overlord, the best thing to do would be to present yourself as trying to free the good people. Your best bet in that scenario would be to slowly start taking over the kingdom, bit by bit. The people will hail you as heroes, and if you treat them fairly, you'll be fine.

If kingdom B has a ruler who's fair and just, however, that's going to be a bit of a problem. Simply conquering them may go badly, because the people will hate you. It might be a better idea to poison the king (and any noble and just children of his that might have a claim to the throne). Orchestrate chaos as the noble houses all fight for the throne, then come in as a conquering army trying to bring peace to a troubled land.

No matter what you do, though, follow the golden rule of ruling: Pay your army and feed your people. Do that, and everything else is just fluff.

[Balyano]

No matter what you do, though, follow the golden rule of ruling: Pay your army and feed your people. Do that, and everything else is just fluff.

Might I suggest a corollary? Pay their army and feed their people.

[rlc]

Other shenanigans:
-Have the spiders attack a town Mongol style (kill everyone but a couple people who will run to the next town to tell of the horrors)...but the party is there to go and "save the day by chasing the spiders off"
-Charm one of the kings
-Since it's a holy war, get people to convert to the religion and further strengthen the forces. If you're the DM, make it into a Crusade type of deal where another religion can reasonably be seen as an enemy. Maybe the holy land thing or something.

[Celcey]

Since it's a holy war, converting people is a good idea, but it's probably better to do it before you attack. Send out tons and tons of missionaries to try and convert people beforehand, and when you finally arrive to "cleanse the land," they'll see you as saviors. When you do attack, give special privileges to the converts/anyone of your religion, but don't try and oppress the people who don't. They may rise up and rebel.

[Kornaki]

Are you looking for tactics or strategy? Most of the posts here deal with the latter.

If the spiders have some sort of web ability, getting the enemy into a chokepoint (for example a canyon, or a road in a heavily forested region) and webbing the front lines would leave you free to employ volley fire with archers and your magical spells. Area of effect spells would be particularly effective.

Your sorcerers are obviously the bulk of your strength. Reverse gravity on a tightly packed group of enemy units would be devastating if they are not prepared for it. You can potentially use it as a weapon against flyby attacks from the dragon, your DM will have to rule what happens if it flies through the affected area (hopefully you can at least keep the dragon away from your army during battle).

Wall of stone plus cloudkill could also be a nice weapon to use. Have a couple sorcerers cast wall of stone on the back ranks and flanks, and then cloudkill the front ranks and kill the whole army in one tidy swoop.

[Knaight]

Your biggest problem is that holding territory is going to be extremely difficult with your numbers. You might be able to take out opposing armies, but actually controlling an area needs boots on the ground which you don't have. Currently you have an issue wherein you can take an area, you leave, and then the populace just goes back to doing whatever they were doing before, which is pretty much useless in the context of a holy war.

I expect you also have money. So, there's an obvious solution to this problem, provided that the characters are the right sort of evil - secret police/inquisitions. You need paid informants, who keep track of goings on, report heresy/rebellion/whatever, and get back to you. You need some sort of mobile force who comes and deals with these people. You need to set up your informants to watch your other informants and keep them honest. Eventually, the informant network can be expanded to include enforcement as well, particularly if higher ranking people are suborned.

The result is a nightmarish dystopia, but I suspect that's the goal in the first place, as the campaign seems focused on the villainous people.

[Celcey]

You need paid informants, who keep track of goings on, report heresy/rebellion/whatever, and get back to you. You need some sort of mobile force who comes and deals with these people. You need to set up your informants to watch your other informants and keep them honest. Eventually, the informant network can be expanded to include enforcement as well, particularly if higher ranking people are suborned.

The result is a nightmarish dystopia, but I suspect that's the goal in the first place, as the campaign seems focused on the villainous people.

All this is true. HOWEVER, if you want to make an empire that's going to last, don't oppress the people- especially in the type of world where you kill the wrong kids parents and they come back to kill you (approximately) 17 years later. Informants are all well and good, but it's how you deal with the people you don't like that can make or break your leadership. Show mercy to the random commoner who tried to kill you? People wonder what exactly he's fighting against. Kill him? Everyone hates you, and will do all they reasonably can to oppose you.

[Vogonjeltz]

Long story short, the party very recently began an evil but holy crusade of conquest.

I'm looking for ideas for tactical shenanigans as we take our fledgeling army and destroy our enemies.

The army currently stands at:

50 magical spiders (stats unknown)

35 lvl 13 sorcerers (specific stats and spells unknown, but surely flexible)

and probably 100 commoners in the process of training.

Enemy armies are likely to be about 250 - 750 strong, quality unknown. At least one young-ish dragon is in play for one of the opposing nations. So you have a sense of scope.

I'm hoping to cover bases I haven't thought of in taking the holy crusade across the land.

As Gwendol said, giving useful advice is contingent on knowing some key information.

1) What is the party's relationship vis a vis the army and its membership? (Leadership? Do they lead by virtue of strength? Divine Right? Charisma?)

2) What level of control do the players assert over the army and its membership? (RTS level, where the DM actually lets them choose how the army reacts? Or do the players provide orders and it's up to the DM to determine how well the army is able to carry those orders out?)

3) What is the cause? (What are its end goals? Do the players share those goals?)

Some food for thought:

1) How do you plan on expanding the army? (Enslavement? Conscription? Open hiring?) How will you feed it? Pay for it? Logistics.
2) Defeated enemies. This ties into point #1: Prisoners? Ransoms? Thralls? No prisoners? For fantasy comparisons: The Ur-Quan or the Kohr-Ah? (Star control II references)
3) Non-violent expansion: You mentioned this is some kind of evil religious crusade. Does the group/deity you're doing this for have acolytes they can send forth to convert nearby populations? It would be helpful if you had sympathetic followers in the areas you plan to eventually attack, or even in areas you're not attacking to undermine the will to oppose you.

[Inchoroi]

I'd dearly love to hear more about this campaign.

Without specifics regarding opposing forces, money and material (both you guys and the others), you can't get much in the way of strategic ideas.

Tactical ideas, however, are a bit easier, but will be up to you to choose when you use them. One idea that hasn't been mentioned yet is a sorcerer-led small group, which 5-7 cannon fodder stand with the biggest shields they can carry in front of the sorcerer, while they stand back and lob the biggest, and longest range, spells in their repertoire. Additionally, siege equipment will be your party's friend; you can make up for the lack of numbers with better equipment, up to a point.