The following block, items, and functionality do not fit in any particular age, but rather are general additions to Minecraft accessible to the player at any time:
Dragon Orbs: When monsters or animals are killed by something other than Steve, they will drop glowing red orbs, similar to XP, upon death. These Dragon Orbs may not be interacted with directly, but if passed through a Hopper with a Soul Sand filter, will be converted into XP orbs for your use. This facilitates the collection of XP through mob traps and through other methods that would not normally be available to the player.
Vine Traps: One of the simplest forms of traps is to simply cover a pit with some foliage to disguise it. Vine Traps allow you to employ vines for just this purpose, as monsters and animals will think they are about to step on a solid block, only to fall right through them. These effectively replace the use of signs in drop-based mob traps providing a stackable, easier to place, and more intuitive alternative.
Wool Slabs: Wool Slabs may be created out of any color wool for all your decorating needs. In addition to providing aesthetic versatility, they may also come in very handy when using the Block Dispenser as a ROM by providing 16 color-coded off-bits. Wool Slabs may also be recombined into wool blocks either by placing one on top of the other, or by placing 2 in the crafting grid.
Dirt Slabs: The ultimate landscaping tool! Dirt slabs may have grass may grow over them just like with regular dirt blocks, allowing you to sculpt the perfect lawn. Like Wool Slabs, they may be recombined into regular dirt blocks at will by placing 2 of them in the crafting grid.
Detector Rail Variants: While the detector rails were a nice addition to the game, one common complaint is that they can’t detect the contents of a minecart. These variations on the detector rail allow you to do just that. The wood version detects all carts passing over. Stone (the regular ones) have been modified to detect carts containing *something*, whether that be a chest, furnace, mob, or what have you. Obsidian rails *only* detect a cart containing a player. This can be extremely useful in routing carts to various locations in an automated rail network.
Wolf Chops: Finally! A use for wolves! I guess I lied about never adding any features to them
Dung: Another use for wolves! Wolves periodically produce dung as the result of a mysterious biological process. While they tend to only output occasionally, they will only do so if they have been fed since their last production cycle. Wolves, being shy creatures by nature, also prefer to produce dung in the dark. Wolf Dung is extremely valued for its many uses, and is the substance many wars have been fought over in ancient civilizations.
The Companion Cube: With advanced artificial intelligence that prevents it from running off cliffs (or pushing you over them), the Companion Cube is the ultimate virtual pet! While it doesn’t require food or water, it loves to be placed (…or reassembled after a mishap…or being put out of its misery), and will definitely appreciate the occasional pat on the head or a bit of sympathy now and again. Always supportive, and without a complaint, be sure to take the Companion Cube wherever you roam!
Companion Slab: While nigh-indestructible, even the Companion Cube has its limits, and the Companion Slab represents one of them. However, a Companion Slab may be a pleasant alternative for small homes that can not accommodate a full-sized pet, as well as being handy for helping to reach items on high shelves.