Bamboo pieces can be used for building and decoration, for climbing, to negate fall damage, and even some kind of door by placing them into the game world.
Bamboo is the first block inside the game that acts as a doorway that allows players to easily pass through and at the same time keeps chasing Creatures at bay without needing any sort of prior player interaction (different from doors or wicket gates that have to be opened and closed).
The other more common use for Bamboo is as ladders (no matter if rotated horizontally or vertically) and also as a minor Goo block landing system if laid in the horizontal.
How to obtain
Bamboo can be crafted in your Crafting Menu (to be opened by typing "Q" as the default key), but only after the according crafting recipe has been unlocked by claiming the Forbidden City Bundle in the Store for free.
Already crafted of Bamboo are included in the Forbidden City Pack and building kits for Chinese-themed Blueprints, but these Item Packs do not unlock nor contain the crafting recipe for Bamboo. Already crafted Bamboo pieces can also be bought with Coins (obtainable via ingame Store) as parts of (customizable) building kits for Blueprints.
Simply obtaining already crafted blocks / objects will not unlock their crafting recipe though.
How to unlock the crafting recipe
The Bamboo is part of the Forbidden City Bundle that was introduced to the Store with update R52 on February 14th 2018, and can only be crafted in the Crafting Menu (to be opened by typing "Q" as the default key) after claiming this Forbidden City Bundle in the Store for free. There is no other way to obtain this crafting recipe.
After claiming the Forbidden City Bundle, the (already unlocked) crafting recipe for this item will be permanently added to your Crafting Menu, where it will keep being available even on game worlds where the world option "world bound recipes" is enabled.
How to craft Bamboo
To craft 8 Bamboo pieces at a time you'll need:
How to use Bamboo
Bamboo has to be placed into the game world to be of use. It can be used for building, for decoration, for climbing, for cushioning, for jumping, as a door or some kind of cage.
You cannot nor will you need to wire Bamboo to any activation devices to keep acting as a door. Still please note that Creatures are able to hop on top of one piece of Bamboo or two Bamboo pieces stacked on top of each other, so to fence Creatures in, at least three Bamboo pieces have to be stacked.
Bamboo can be used as ladders, no matter if rotated horizontally or vertically, and also as a minor Goo block landing system if laid in the horizontal.
Pieces of Bamboo can be placed for climbing vertically. It is very easy to place pieces of Bamboo as ladders on top of each other while climbing upwards without requiring any blocks as a scaffold. However placing a Bamboo piece beneath the one the player character is standing on is extremely difficult, if not completely impossible.
Bamboo can be fully rotated into all directions by holding R (as the default key) and moving the left mouse button. The chosen rotation angle can then be "locked" too by simply typing "r" while looking at a rotated item, then all Bamboo pieces of the same stack will be placed facing the same direction.
Even if you rotate Bamboo pieces upside down and connect them, they will keep on working as a ladder like normally. Bamboo can also be placed sideways and can still be used for climbing this way. You can climb Bamboo as a ladder even if you leave free spaces the size of one block in between the Bamboo pieces, but it's advisable to start with two pieces of Bamboos stacked on top of each other at the lower base of the ladder, otherwise it will be difficult to start climbing bottom-up.
It is easy to fall from a ladder made from Bamboo by passing through it if it's not placed against solid blocks, or by taking a step too far sideways; so it is advisable to take care while climbing.
Different from actual ladders, Bamboo will not give player characters a little push forward on their top side and such cannot be used for the creation of roller coasters.
On the other hand, if you rotate pieces of Bamboo so that they lie flat on the ground and make your player character step on it from the side, the character can be flung high up into the air. This usually only works if the long side of Bamboo is stepped on, not at the upper or bottom ends with their tubular openings visible.
When jumping on a ladder made of Bamboo or landing on them while flying, the player character will "stick" to the ladder and will not take falling damage. Because of this, Bamboo can be used to negate falling damage when placed on the ground just like all liquids and Blocks of Goo. For this, it is advised to rotate Bamboo and put it down flat on the ground with its frontage looking upwards.
Player characters can use Bamboo to make their way hand over hand along a ceiling, but this is not as easily accomplishable as with actual ladders. It will work a bit better if the pieces of Bamboo are placed upright instead of being laid flat against the ceiling.
Creatures cannot climb ladders made from Bamboo, however Bamboo can only be used as a substitute for Fences if you stack at least 3 pieces of it together, because Creatures can still simply walk over one piece of ladder or can jump onto two ladders placed on top of each other just like on any kind of common cubic block.
Since Creatures can just walk across the upper end of ladders made from Bamboo, they can also use them as "bridges" to cross small gaps as well if ladders are placed between two blocks.
Standing on a ladder made from Bamboo does not make a player character invulnerable, even though aggressive Creatures usually ignore player characters who are on a ladder and out of their reach. Many aggressive Creatures will stop hunting the player character as soon as s/he steps up or down a ladder and will then retreat a little. However some aggressive Creatures will follow player characters and then wait in front of the ladder, hitting at the player character as far as they can reach.
Standing on a ladder makes throwing Explosives hard to accomplish, so it usually is necessary to reach the top of the ladder to be able to throw anything accurately.
Bamboo can be picked up without the need to equip any Power Cells. Of course you won't be able to pick up such blocks on game worlds, on player claims or in Adventures where your Permission rank is not sufficient (mainly when you are merely a visitor), which can only be changed by the owner of the game world, the respective claim owner or Adventure creator.
Other than that, Bamboo can also be put on display by placing them into the slots of display containers like Placemats, Stone Wall Shelves, Hidden Temple Altars, Galactic Grav-Chambers, Frozen Containers, Holiday Decorative Trees, Snow Buried Containers or the like.