Things You'll Need
Instructions
Craft some sticks. Press the "X" button to open the crafting menu and move two wood planks into the bottom center and middle ingredient slots. Click the stack of sticks when it appears on the right to select it and then drop it into an inventory slot. Repeat as necessary to make more sticks.
Craft some fence posts. Open the crafting menu and arrange six sticks in the bottom six ingredient slots. A stack of two fence posts will appear on the right. Click it to select it, move it to an inventory slot and then repeat as necessary to make more posts. You may need quite a few fence posts depending on the size of the entryway where you want the portcullis.
Prepare the entryway for construction. Place a line of dirt blocks underneath the entryway that spans its entire width and is exactly one block shorter than the entryway's height. Your "Minecraft" character will be too tall to stand inside the entryway now, so build up another line of dirt blocks just outside the entryway. This will allow you to stand alongside the line of dirt blocks that goes under the entryway.
Construct the portcullis. Place a line of fence posts on top of the dirt blocks. The fence posts will automatically connect themselves to each other and each side of the entryway. Destruct the level of dirt blocks directly beneath the line of fence posts and repeat. The fence posts will join to the sides and the fence posts above them.
Repeat the previous step until all the dirt under the entryway has been replaced with fence posts. Your portcullis is now complete. If you haven't already, you can now destruct the second line of dirt blocks that you made at the end of the third step.