Climbing

Certain things can be climbed. For example, you can climb ladders, apple trees, and walls.

Climbing requires stamina and takes time. The surface you're climbing (hard coded but eventually will be materially based) and your encumberance all affect the difficulty level, which is overcome by a comperably high skill level.

You can jump down if a location is below you, you'll take damage based on your agility + the distance to fall (jump down locations added in link)