The structures that make up a castle serve practical purposes, especially in wartime, because most castles were built as forts. To create a castle in "The Sims 3," focus on the different parts common to most castles. Many castles have moats to prevent enemies from scaling the walls. Those outer walls surround the entire castle complex. A gatehouse serves as a fortified entrance to the complex, often accompanied by towers on either side. At the centre of the castle stands the keep, the last refuge for castle inhabitants if the walls are breached.
Click the "Options" menu after you've started your Sims game and choose the command "Edit Town."
Click a large empty lot on the map, then click the "Build/Buy" icon on the Lot Details window that pops up. This zooms you in to the lot and places you in Build Mode. A grid across the land helps you line items up.
Click the "Ponds" tool on the Building control panel at the bottom of the screen to create the moat.
Hold the mouse button down as you drag to create a circle of water around the entire perimeter of the lot, leaving a tiny isthmus of land at the front of the lot for access to the castle.
Click the "Back" button that looks like left-pointing triangle to exit the "Ponds" tool and return to the main Build Mode screen. Every time you need to change building tools on the following steps, click the "Back" button to return to the main screen.
Click the "Floors and Ceilings" tool and click the "Wood" tab. Choose a style of wood to cover that isthmus of land and simulate a drawbridge on the lot. Click the lot to create a rectangle that stretches from the edge of the lot to where you want to start your castle gatehouse.
Click the "Walls" tool. Click on the lot and hold the mouse button while dragging to draw walls. Use the grid on the lot for guidance. Make an octagon in each of the four corners of the lot. Make sure they line up with one another.
Connect the octagons to one another with two straight walls that stretch from the edges of their sides that face each other. The end result is a long rectangular hallway between the octagons.
Create the gatehouse by drawing a small rectangle with the Walls tool at the edge of the wooden floor you placed on the isthmus. The gatehouse should touch the castle wall just as a porch touches a house.
Create a rectangle or octagon near the centre of the lot to be the castle keep.
Click the "Go Up a Floor" button on the left side of the Build Mode control panel. Add walls on top of all the walls you created on the first floor.
Repeat Step 6 to create a third, fourth and fifth floor, but add walls on top of the octagons only at the corners and the keep. The gatehouse and side walls of the castle should be shorter than those other areas.
Click the "Go Down a Floor" button to return to the third floor. Click the "Half Wall" option in the "Walls" tool window and add a half-wall to the tops of the castle side walls between the corner octagons.
Return to the first floor. Click on the "Floors and Ceilings" tool and select a stone style for the floors.
Hold down the "Shift" key and click inside the castle to add stone flooring. The "Shift" key allows you to quickly add the pattern to all squares of the grid in an enclosed area. Repeat this on all levels of the castle.
Click the "Wall Coverings" tool. Choose the "Masonry" category and select a style of stone or brickwork for the walls of the castle.
Hold down the "Shift" key and click the outside of the castle to apply the pattern to the exterior walls. Repeat on the inside of the castle to apply the pattern to all interior walls.
Click the "Roof" tool. Make sure the radio button next to "Auto Roofs" is "Off." Select a "Conical" or "Octagonal" roof style from the panel of options and click and drag across the tops of the octagon towers to place roofs on each. Add a roof to the Keep in the same manner. If the Keep is rectangular, use the "Mansard" style roof. The gatehouse roof remains flat.
Click the "Door" tool. Select an old, wooden-style door from the panel of options. Click on the gatehouse and the Keep to give them front doors. Add doors to each of the octagonal towers for access to the hallways.
Click the "Stairs" tool. Select the stone stair style and click to place at least one set of stairs on every level of the castle.
Click the "Windows" tool. Select a cathedral-, Gothic- or lattice-style window and click the walls of the castle to add them as needed.
Click the "Options" menu and select "Edit Town" to return to the main map screen.
Click the "Options" menu again and select "Save" to save your progress so far. Repeat these last two steps frequently as you're working so you don't accidentally lose any work.
Floor plans from real castles may assist with your design in helping you place walls and structures in realistic locations. Use the Build Mode Basement tool to create a subterranean level that could serve as a dungeon. Add crenelations to the top of the gatehouse roof with the "Fences" tool in Build Mode. Click the "Shrubs" tool in Build Mode, select the "Hedge" plant and click to place a hedge inside the castle walls for a courtyard. If you're feeling creative, use the hedges to make a maze. If you have installed "The Sims 3: World Adventures" expansion pack, some of the foreign furniture and decorations have that "ancient" look that is appropriate for a castle. The Electronic Arts store offers a "Sims 3" building kit that contains exterior pieces to build a medieval-style castle similar to what you see in "The Sims Medieval" game. A second set contains several interior pieces to decorate your new place. You cannot save until you exit "Build Mode."
Because castles need a lot of room for inner courtyards, moats and keeps, they don't work well on small lots. For the castle to make a suitable home for Sims, you need to some modern amenities such as kitchen appliances and bathroom facilities. You could place these items inside the keep or one of the octagon towers.