Platforms

Platforms are an alternative to blocks that can be walked upon, but which allow movement through the space they occupy.

The player normally stands on platforms, but can go down through a platform by pressing the down key while standing on one. If a platform is just a few tiles above a block floor, players can walk or jump horizontally through the space occupied by platforms, only treating the platform as "solid" when standing upon them. Walking enemies will walk upon or pass through platforms depending upon whether the player is above or below the platform. Flying enemies like bats will fly up through them, but not down. Other enemies, including harpies, ignore them, entirely. NPCs will always climb up platforms.

Weapons will travel through Platforms. Any hook will grab them. Liquids flow through platforms, and lava will destroy most platforms upon contact. Sand will be supported by platforms, and sand will stop liquids, so it is possible to stop liquids from traveling through platforms by placing sand on top of them.

Because of the high mobility a player has while on them, platforms can be used in a variety of ways: as a bridge across gaps that players can descend through without destroying, for roof access that keeps most enemies from getting through, or to create a fighting area above most enemies that players can shoot through while out of reach of enemies. Also, since Piggy Banks, Chests, Crafting Stations and other Furniture can be placed on them (except for torches, Crystal Shards, and cooking pots), they can be used as a shelving to pack more pieces of furniture into a smaller space.

As of version 1.2, there are a great many types of platforms. Previously, (and currently, in the console version,) only wood platforms existed. Virtually all platforms are functionally identical, and differentiated only in what materials are used to craft them, and their aesthetics.

Obsidian Platforms are different in that they do not break upon contact with lava the way most platforms do.

Non-craftable
All but the Obsidian stylized variants are found in the Dungeon