Plants vs. Zombies (video game)

***Plants vs. Zombies*** is a 2009 tower defense video game developed and published by PopCap Games. First released for Windows and Mac OS X, the game has since been ported to consoles, handhelds, and mobile devices. The player takes the role of a homeowner amid a zombie apocalypse. As a horde of zombies approaches along several parallel lanes, the player must defend the home by putting down plants, which fire projectiles at the zombies or otherwise detrimentally affect them. The player collects a currency called *sun* to buy plants. If a zombie happens to make it to the house on any lane, the player loses and must play through the level again.

*Plants vs. Zombies* was designed by George Fan, who conceptualized it as a more defense-oriented sequel to his fish simulator game *Insaniquarium* (2001), then developed it into a tower defense game featuring plants fighting against zombies. The game took inspiration from the games *Magic: The Gathering* and *Warcraft III*; along with the movie *Swiss Family Robinson*. It took three and a half years to make *Plants vs. Zombies*. Rich Werner was the main artist, Tod Semple programmed the game, and Laura Shigihara composed the game's music. In order to appeal to both casual and hardcore gamers, the tutorial was designed to be simple and spread throughout *Plants vs. Zombies*.

*Plants vs. Zombies* was positively received by critics and was nominated for multiple awards, including "Download Game of the Year" and "Strategy Game of the Year" as part of Golden Joystick Awards 2010. Reviewers praised the game's humorous art style, simplistic but engaging gameplay, and soundtrack. Upon release in May 2009, it was the fastest-selling video game developed by PopCap Games and quickly became their best-selling game, surpassing *Bejeweled* and *Peggle*. By 2010, it had sold over a million copies worldwide and has since been considered one of the greatest video games of all time. In 2011, PopCap was bought by Electronic Arts (EA). The company laid off Fan and 49 other employees, marking a change of focus to mobile and social gaming. After the buyout, *Plants vs. Zombies*was followed by a series of games including two direct sequels, three third-person shooters, and two spin-offs, most of which have received positive reviews.

## Gameplay

*Plants vs. Zombies* is a tower defense video game in which the player defends a house from zombies. The lawn is divided into a grid, with the player's house to the left.The player places different types of plants on individual squares of the grid. Each plant has a different style of defense, such as shooting, exploding, and blocking. Different types of zombies have their own special behaviors and their own weaknesses to different plants. For example, Balloon Zombie can float over the player's plants, but its balloon can be popped by Cactus. Other examples of zombies include Dancing Zombie which summons Backup Dancers around himself; and the Dolphin Rider Zombie, which rides on a dolphin to jump over a plant.

The player can pick a limited number of types of plants through seed packets at the beginning of each level, and must pay to place them using a currency called "sun". The player collects sun by either clicking on sun icons that randomly appear over the lawn, or by using certain plants that generate sun, like Sunflowers and Sun-shrooms. Each type of plant recharges between each placement at various speeds. A shovel can be used to dig up and remove plants. Positioned at the left end of each lane is a single-use lawnmower; if a zombie reaches this end, the mower activates and kills all zombies in that lane. If a zombie reaches the end of a lane whose mower has already been used, the player has to restart the level.

### Adventure mode

There are five stages in the Adventure mode, each comprising ten levels. At the end of nearly every level, the player collects a new type of plant to use in subsequent levels. On the first level of stage two (level 2-1), zombies begin to occasionally drop in-game money when killed. After level 3-4, the player can spend the money at an in-game store called Crazy Dave's Twiddydinkies. Crazy Dave offers boosts that the player uses to upgrade already-placed plants and gardening tools for the player's Zen Garden. It is unlocked after level 5-4 and allows the player to water and maintain a group of plants, which are obtained as loot from killing zombies or purchasing them through his store; in return, the plants generate money for the player. Every stage's fifth level has a mini-game challenge, often utilizing a conveyor belt that gives various plants to the player. On every stage's tenth level, the player receives plants from a conveyor belt. Stages one, three, and five occur in daylight, while stages two and four take place at night.

During the nighttime stages, the player uses the lower-cost fungi plants due to the lack of natural sun generation at night.Stages three and four take place in the house's backyard, which has six lanes (unlike the usual five lanes) and features a pool taking up the middle two lanes. On the pool, plants are placed on top of Lily Pads which, unlike most plants, can be placed directly on pool lanes. Stage four has fog that obscures most of the lawn. Stage five takes place on the house's roof. This setting has the player use catapult plants, instead of the standard shooting plants, to account for the roof's upward slope.

Adventure mode's last level pits the player against Dr. Zomboss, an evil scientist and the zombies' animator. He crushes the player's plants by having his Zombot crush the plants or throw vans at them, and can place fire and ice balls that roll across a lane. The player subdue these balls with Jalapeños and Ice-shrooms. After completing the Adventure mode, the player can play it again, this time with plants unlocked during the previous play-through, and with three randomly selected plants to begin each level.

### Other game modes

Three additional modes—Mini-Games, Puzzle, and Survival—become available once Adventure mode is completed. In Mini-Games mode, the player selects from a collection of twenty mini-games. These levels pose the player with unique challenges, each using some gimmick—often variants of a conveyor belt that gives the player certain plants. In Puzzle mode, the player selects from two types of levels: "Vasebreaker" and "I, Zombie". In "Vasebreaker", the player breaks open a set of vases, each containing a plant or a zombie. The level ends when all the vases are smashed and all the zombies are killed. In "I, Zombie", the player places zombies to get past pre-placed cardboard cut-outs of plants, aiming to eat the brain at the end of each lane. Survival mode offers a selection of levels in which the player chooses plants to defeat increasingly challenging waves of zombies.

## Development

### Concept

*Plants vs. Zombies* was designed by George Fan. Imagining a more defense-oriented version of one of his previous titles, *Insaniquarium* (2001), and having played some *Warcraft III* tower defense mods, he was inspired to make a tower defense game. Fan considered a sequel to *Insaniquarium* for the Nintendo DS, each screen would represent a separate fish tank—one on top of the other. Aliens would attack the top fish tank and, if successful, would break into the bottom fish tank. Gameplay in the top tank would focus on defense against the aliens, while in the bottom tank it would revolve around resource generation, akin to *Insaniquarium*. But inspired by *Warcraft III*'s towers, he felt that plants would make good defensive structures. He wanted to bring new concepts to the genre and believed the fact that enemies in tower defense games would never attack the towers was unintuitive. To address this, he began designing the five- and six-lane setups that would later be used in the final game. Enemies were at first the aliens from *Insaniquarium*, but while Fan was sketching concept art, he drew what he considered "the perfect zombie", and the theming was reworked. Fan went with using zombies instead of aliens in order to make the game stand out from other video games using plants.

*Insaniquarium* substantially influenced the development of *Plants vs. Zombies*. The games have similar pacing, determined by the "drip-feeding" of pets and plants respectively, and choosing plants at the beginning of each *Plants vs. Zombies* level is analogous to choosing pets in *Insaniquarium*. Fan also took inspiration from the film *Swiss Family Robinson,* in which a family defends themselves and their home against pirates. Fan included elements from the trading card game *Magic: The Gathering*, which he had played with his girlfriend, Laura Shigihara. Showing her how to customize their card decks inspired him to design *Plants vs. Zombies* with seed packets—instead of his original idea of a conveyor belt that gave random plants—due to the seed packet system's greater complexity. While the conveyor belt was dropped from the more common game mode, it remained a special element in select levels. The use of multitasking between lanes was influenced by and was featured prominently in the old arcade game *Tapper*.

When the game featured aliens, its working title was *Weedlings*, but Fan thought the name a poor fit because of how many gardening-themed video games were being released at the time. It was renamed *Plants vs. Zombies* as a placeholder after the enemies were changed. The planned name for most of development was *Lawn of the Dead*, a pun on the title of the George A. Romero zombie film *Dawn of the Dead*. Romero did not permit usage of the name, even after a plea from Fan, who sent Romero a video of himself dressed as a Zombie Temp Worker grunting and programming on a computer, subtitled with references to runtime errors. There were many other candidate names, including *Residential Evil* and *Bloom & Doom*, the latter of which was used as the branding on the in-game seed packets.

### Design

*Plants vs. Zombies* was initially designed by Fan alone. Because Fan was a full-time employee at PopCap Games, the video game company helped build up a small team consisting of a composer (Laura Shigihara), a programmer (Tod Semple), and an artist (Rich Werner). Fan was based in San Francisco, while Werner was in Seattle. Stephen Notley is credited as being a writer for *Plants vs. Zombies*. He wrote the plant and zombie descriptions in the in-game guide, the Suburban Almanac.Fan found working in small teams to be easier than working in large teams. According to an interview with *Edge*, while searching for an artist, Fan discovered Rich Werner, whose work Fan thought matched with his design intentions. Fan attributed the design's intrigue to its animation scheme; Tod Semple suggested using Adobe Flash, which Fan worried would generate an animation "cut out from paper" and too closely resembling *South Park*, but he was ultimately satisfied, crediting Semple and Werner's talent. *Plants vs. Zombies* was made using PopCap Games's own engine: PopCap Framework. Fan consistently posted updates of *Plants vs. Zombies* every four months in an internal forum within PopCap Games called Burrito, where he accepted feedback from the employees of PopCap.

When the concept of *Plants vs. Zombies* was first established as a sequel to *Insaniquarium*, Fan wanted to make a game where the aliens invade the player's garden. Originally, his intent was to make a gardening game where plants are grown as an investment to afford defenses against an alien invasion. After Fan created the "perfect zombie", the enemies were changed from aliens to zombies. He trimmed the concept of simultaneously defending and maintaining the garden, feeling that the repetitive gardening detracted from the main gameplay. Simplifying the gardening system, Fan restructured the game's main aspects to fit better into the tower defense genre, and later added further elements inspired by other games. Fan enjoyed the idea of plants defending against the zombies, combining two distinct species that were not yet touched by other game developers at the time. Plants playing as the role of towers made sense to him, acting as stationary defense against the recurring waves of zombies. Zombies were designed to move in the current linear five- and six-lane system in the final game, allowing the enemy zombies to interact with the defensive plants, a refinement in the game that Fan felt worked as a unique gameplay mechanic to make *Plants vs. Zombies* stand out in the tower defense genre amongst other tower defense games popular at the time.

*Plants vs. Zombies* took three and a half years to make. Much of the first year of development focused on Adventure mode. Semple began working on ideas later used for Mini-Games mode. Some ideas for the Puzzle mode section were later modified and moved into Adventure mode: "Vasebreaker" and "I, Zombie", for example, came from single-level concepts for Mini-Games mode. During testing, Fan found that the Mini-Games and Puzzle modes detracted from a focus on Adventure mode, so he locked most additional modes, requiring advancement within Adventure mode to unlock them. Later, the development of *Plants vs. Zombies* consisted of Fan testing the game and writing down notes of what could be done to tweak it before sending them off to Semple. The last year of development had the team fine-tuning *Plants vs. Zombies* before release.

One of the critical aspects of the development was designing *Plants vs. Zombies* to be balanced between hardcore and casual gaming. Fan designed the tutorial to be simple and merged within the game to attract casual gamers. It had the player learning by performing actions, rather than reading about how to do the actions. The in-game messages were also made to be as short and easy-to-read as possible; with the dialogue from Crazy Dave being broken up into small chunks of text to match this. The in-game messages were also designed to match a player's skill set; an example being the message telling the player to place Peashooters further to the left would only pop up in an early level if a Peashooter was placed towards the right of the lawn and was eaten. The team discovered that newcomers to the genre of real-time strategy often had difficulty learning the importance of sun collection. The price of the income-generating Sunflowers was halved, encouraging the player to buy them instead of the attack-only Peashooter. The change forced restructuring of the balance between plants and zombies, a move that Fan said was worth the effort.