Note that there are a few blocks that won’t stop the chest from being opened if they’re placed on top of it. These include: water, lava, leaves, cactus, glass, snow, stairs, farmland, cake, beds, fence, another chest, a torch, rails, signs, and a few more (translucent blocks). As of Minecraft 1. 13, you can place more than two chests next to each other.
You must place both chests from the same direction for them to connect into a large chest. If you hold shift while placing the chest, it won’t connect and make a large chest.
Note that you can put two trapped chests next to each other, to make a large chest.
The top three rows in the chest correspond to the western or northern chest block. The bottom three rows correspond to the southern or eastern chest block. In the large chest, you’ll find the items organized into the southern or eastern side, which will depend on the orientation of the chest.
Left clicking will help you to collect all of the items in the slot. Left click again to place items. Right clicking will let you take just half of the items in a slot. Right click to place a single item.
