Editing 40d:Moat

The term "'''moat'''" refers to a defensive ditch that optionally may be filled with [[water]] or [[magma]]. There is no in-game structure called a "moat", but any [[channel]] defensively placed to block invaders, whether around your entire fortress or just a short one in front of a bridge, can be considered a moat.

A moat is an effective way to keep [[siege]]s away from your [[wall]]s and [[fortification]]s. This gives your [[marksdwarf|marksdwarves]] protection from enemy archers, and protects your [[door]]s and [[bridge]]s from [[building destroyer]] creatures such as [[troll]]s.  A well-designed moat  prevents the passage of any creature traveling on foot, though flying creatures, of course, just don't care.

''(Remember that any creature can path diagonally across tiles, so there can be no diagonal path for your moat to be effective.)''

It is not necessary to fill a moat with [[water]] for it to be effective - dry moats work just fine. While creatures knocked into an empty moat will be unharmed, those knocked into one with water will drown, but recovering items dropped into a water-filled moat is a challenge.  

A [[water]]-filled moat can freeze in cold [[weather]], allowing foot traffic across the [[ice]].  If this happens, the [[ice]] can be mined out, returning the moat to a dry state.  A more elaborate method would be [[pump]]ing the water out before [[winter]] and back in once the Spring thaw comes. Yet another method is to dig a 2 z-level deep channel and fill only the bottom z-level with water, which also works against swimming creatures. 

A [[magma]]-filled moat is the deadliest: It does not solidify in the winter and it instantly kills all that fall in, friend or foe, along with any items.  (Dwarves in combat have a habit of dodging off the edge of bridges and walk-ways unless there is a solid barrier like a [[wall]] or [[fortification]] to stop them - something to consider.)

If you wish to combine safety and offensive value, consider a channel lined with your favorite [[traps]].

A very deadly combination is to first create a moat, then put a retractable bridge across it. On the outside of the moat, next to the bridge, put [[pressure plate]]s surrounding the bridge. Link them all to the [[bridge]], and watch as invaders step on the pressure plates, then step on the bridge, the bridge retracts, they fall in, and drown/burn.

==Reverse Moat==

Digging channels for a moat can interfere with the first underground layer of your fortress. But it's possible to get the benefits of a moat without channeling from the surface. Construct two walls around your entrance, and connect them by a [[drawbridge]]. Build [[ramp]]s or [[stair]]s on the inside of the inner wall, and the outside of the outer wall. To cross the moat, a creature has to climb up, cross the bridge, and climb back down. If the bridge is wide enough, and lined up with three ramps on either side, merchant [[wagon]]s can enter.
    _....._
 __/ |___| \__          ..... = drawbridge     / <small>(or)</small> \ = ramp

==Trap Moat==

Essentially, the Trap Moat is an empty moat with a retracting bridge. However, the inside of the moat is filled with upright [[menacing spike|spike]] [[traps]]. The idea is, when enemies get on the bridge, you pull the [[lever]] to retract it and pull the lever to spring the traps. When they fall, they get perforated. However, there's ramps at the end of the moat so friendly dwarves can get out and surviving enemies can futilely try to cross the bridge before they bleed out.

==Dungeon Moat==

Like the trap moat, only the channel is filled with cage traps instead so you can expand your [[zoo]].  If you use this strategy, it is recommended that you connect all your moats together, so that if all the cages in one moat are full, hostiles will (hopefully) wander over to the bottom of another moat and get caught.

You will need an entrance into the network to retrieve captured enemies.  This entrance should also be controlled via drawbridge/moat access, and the moat it uses can connect via stairway to the dungeon you've already built.

You might also want to include some upright spike traps in case all the cages are filled.  Otherwise you could potentially have the entire enemy army wandering around in your fort's dungeon.  Of course, that might be a problem you ''want'' to have.

This idea would be more fun if you had a reliable way of getting enemies inside the dungeon.  For example, you could restrict entrance to your fortress along a narrow passageway, and then replace the passageway with a retracting bridge over your dungeon.  (Hint: You'd have to build the retracting bridge first, then turn the bridge into the only means of getting into the fortress using channels.)

DISCLAIMER: I haven't actually tried any of this out yet; something will probably go wrong (for example, enemies that fall into the moat might be too stunned to wander around and find an open trap.)
[[Category:Military]]
[[Category:Fortress defense]]