Erosion is mostly visual, making the world feel more rundown and overgrown, along with some functions that will require the player to adapt and maintain.
Vines growing up walls, which can be removed with an axe.
Cracks begin to appear on the walls, getting bigger over time. This does not currently reduce the structural integrity of a building. Plaster and paint can be used to repair cracks.
Tall grass will eventually grow on every outdoor tile. This can be removed by hand, or with a shovel.
Trees will sprout, starting as small saplings and eventually tall fully grown trees. This is a renewable source of logs and branches, however can block the path for vehicles.
Having trees close to your base can prove dangerous, since zombies can hide behind them and sneak up on the player, potentially biting them.
Erosion started out as a mod created by now developer TurboTuTone (Turbo) released in late 2013 on The Indie Stone forum. Turbo later joined the team in the second half of 2014, with the implementation of erosion being his first task.