+The Basics+
Castle Siege is in essence, exactly what it sounds like. One team, the stalwart remnants of the castle's army, is holed up in a giant castle that spans the majority of the map. Their only goal is to hold off the endless horde of attackers for as long as possible. The gameplay centers around one simple fact: You really don't want to let any of those pesky invaders in your castle! The gametype is a simple one-sided VIP variant, with the VIP on the attacking team representing a squad leader or commander of some sort. Points are allotted as follows:
Kill--------1 point
VIP kill-----2 points
Destination-5 points
Rounds are played first to 50, with a time limit of 10 minutes placed on each round. There are only two rounds: so each team gets a chance to play each role. Now, I'm sure you're al eager to explore the gameplay, so let's jump right in!
+Attackers+

You have on goal and one goal only: GET IN THAT CASTLE!
Pictured above is your starting/respawn point. The attacking team has a forced color of brown, while the VIP is forced black. Now, before you just go run off all willy-nilly to go crash your castle, you have an important decision ahead of you: What role do you want to play in the upcoming battle? Caste Siege is equipped with a class selection system for the attackers; you can choose to be a swordsman or an archer every time you respawn.

Should you choose the noble path of the Swordsman (straight where we were looking in the picture of your starting spawn), you'll find yourself in this room. Grab your shotgun, pick up some spike 'nades, and make sure you don't forget the flare! Then head on over to the teleporter and prepare for battle!

Archers will proceed forth into this armory, well-stocked with whatever kind of long range weaponry you prefer. Choose between a BR or Carbine as your primary weapon, and if one is avaliable, you can grab a Sniper as your backup. The two snipers are both set on a 60 second respawn timer. Make sure to stop by the shelves on the far wall for some good ol' frags and either a Bubble Shield or a Regenerator.
Once through the teleporter, you will find yourself at one of two random teleporter spawns outside of the castle. Get ready for some action, and go forth to victory! FOR THE HORDE... or something. You know, whatever gets you goin'

There's what you're up against. It's not that bad, now get in there and get fighting!
+Defenders+
You guys got the hard job... defend the castle! It's important to remember that your castle is... well, under siege. What that means to you is that no supplies are coming in. What THAT means is... weapons don't respawn. So, use your starting SMG whenever possible, and save those grenades, BRs, and precious power weapons for when you really need them. To be fair, ONE BR and ONE grenade will respawn every 45 seconds in each armory, but with 0 extra clips. If you're desperate for ammo, get killin'! Grab some of the weapons your foes leave behind (though they won't have much ammo either)

See all those green corpses? Those were once the valiant defenders of the castle. Then, they apparently decided they were too good for the castle. Moral of the story: Stay in the castle. This pic not a good enough reason to stay indoors? Well, like any castle worth its salt, yours is equipped with a wide array of defensive measures:

If you look closely, you can see a lonely fusion coil headed on its way into some oblivious attacker's face. There is one of these siege ballistae on each side, and they will continually fire upon the advancing attackers outside.

Your main gate isn't left undefended, either. A quick grenade or precise spray of bullets down either side of the drawbridge will blow it to pieces, hindering the assault. The attackers CAN jump this gap, but it'll be close. One misjudgement and they'll end up in the moat (and for kicks and giggles, our moat is filled with fusion coils!)
Also, up above, you can see the buckets of pitch ready to be dumped (in english: more fusion coils). This ledge can be accessed from either rampart, and if you crouch underneath the overhang you can push those coils over the side. If the bridge is out, the fall will set them off. If not, a quick shot or grenade will scatter your foes in a heartbeat.
AND NOW...
+HILARITY!+

Me about to score at the destination! Go Team!

...me immediately after my arrival (I'm the flaming dead one)

Your health doesn't regenerate, so try to avoid losing it to stupid things like the Ballistae

A purely aesthetic catapult. One of the attacker's spawn teleporters is right behind it.

Don't feel too safe up in that tower! Seriously, undeadmarine100 stuck me from the floor. That was ridiculous!

The general level of chaos around the drawbridge.

I believe my plan was inherently flawed... yeah that's me.