In Plants vs. Zombies, players place different types of plants and fungi, each with their own unique offensive or defensive capabilities, around their house, in order to stop a horde of zombies from reaching it. The playing field is divided into 5 to 6 horizontal lanes, and with rare exceptions, a zombie will move towards the player's house along one lane only (the main exception is if it has bitten a garlic, causing it to move to another lane).

Planting costs "sun", which can be gathered for free (albeit slowly) during daytime levels and by planting certain plants or fungi. Most plants can attack or defend against zombies in the lane they are planted in only. In later levels, players can purchase upgrades with different offensive and defensive abilities.