In Plants vs. Zombies, players place different types of plants and fungi, each with their own unique offensive or defensive capabilities, around a house in order to stop a horde of zombies from devouring the brains of the residents. The playing field is divided into a number of horizontal "lanes", and with rare exceptions, a zombie will only move towards the player's house along one lane (the main exception is if it has scented a garlic). Most plants can only attack or defend against zombies in the lane they are planted in. In the game's initial levels, if the zombie reaches the player's house, a one-shot tool (e.g. a lawn mower) can be used to completely wipe out zombies in that lane, but the tool will not be restored until the next level. In later levels, players have to purchase upgrades so as to adapt their lawn-mower to new environments like pools or rooftops.
