The original Plants vs. Zombies Adventure mode has five stages.
Adventure mode is the main progression path in the original Plants vs. Zombies. It takes the player from the front lawn through increasingly unusual battlefields, including nighttime levels, a backyard pool, fog, and finally the sloped roof. Each stage contains ten levels, making 50 standard Adventure levels in the first play-through.
The five-stage structure also controls how the game introduces mechanics and plants. The first stage establishes basic daytime defense, while later stages add darkness, water, fog, and roof combat. The final level of stage five is a boss battle against Dr. Edgar George Zomboss, who attacks with a Zombot and special fire and ice hazards.
Players sometimes confuse the five stages with the total number of levels, or count the later replay as a separate campaign. After completing Adventure mode, players can replay it with previously unlocked plants and a changing selection of starting plants. The stage count itself remains five.