Endless Zone

"The Endless Zones are harder than usual!"

- Penny

Endless Zone (Challenge Zone in the old version) in Plants vs. Zombies 2: It's About Time is unlocked after beating the twelfth day of Ancient Egypt, fourth day of Pirate Seas, third day of Wild West,  fourth day of Far Future, the twelfth night of Dark Ages, twentieth day of Big Wave Beach, and after beating Boss Vase in Vasebreaker. The levels are known as Pyramid of Doom, Dead Man's Booty, Big Bad Butte, Terror from Tomorrow, Arthur's Challenge, Tiki Torch-er, and Vasebreaker Endless. In the game, players start off with three plants (Sunflower, Wall-nut, and Peashooter), four plants in Arthur's Challenge (Sun-shroom, Puff-shroom, Fume-shroom, Wall-nut), and three different plants in Big Wave Beach (Sunflower, Peashooter, and Lily Pad), then they get to pick one more plant at the beginning of each round. They can also choose to start off with 200 more sun, start off with an extra Plant Food, get any free power up (the 2.0.1 update and above) or to recharge Lawn Mowers. Since the 2.0.1 update, a fourth card in the card selection is available. However, it is unrevealed and unusable unless 2000 coins are paid to reveal it.

The player can save and quit in the middle of level or before starting a level, and all their Plant Food are kept from one level to the next one. The player can only buy one Plant Food per level and all Power Ups can be only used once per level too. Currently this effect is no longer in use, most likely as a bug, or possibly because they just want it to be easier due to the presence of Gargantuars. In general, as the player goes through the highest level of all Endless Zones, the tendency to spawn a Gargantuar after killing the first Zombie, will increase. Surely, if the player reaches level 1000 and beyond seven Gargantuars will appear after killing the first Zombie along with its other forces if the level is infested with Gargantuars. Otherwise, it will then spawn a high level zombie like Mecha-Football Zombie in large numbers accompanied by twenty-five Shield Zombies.

Pyramid of Doom
This is Ancient Egypt's Endless Zone. As the player progress through higher levels, the lawn will be filled with large number of tombstones, occupying most spaces and preventing the player from planting any kind of plant. The zombies to watch out for in this Endless Zone are Explorer Zombie, Pharaoh Zombie, and Mummified Gargantuar.

Dead Man's Booty
This is Pirate Seas's Endless Zone. The number and placement of plank bridges vary in different levels. It is easier when there are less plank bridges since there are less Gargantuars to handle. Dangerous zombies in this survival zone are Imp Cannon, Zombie Parrot, Pirate Captain Zombie, and Gargantuar Pirate.

Big Bad Butte
This is Wild West's Endless Zone. As the player progress through higher levels, the lawn will be filled with mine carts that can either occupy two, three, four, or five rows. The minecarts can also occupy many spaces, limiting the player from planting. However, the player can also use these to delay Wild West Gargantuars. Watch out for Chicken Wrangler Zombies, Zombie Bull Riders, and the Wild West Gargantuar in this Endless Zone. Among the other Endless Zones, Big Bad Butte is considered to be the most challenging of all because of mine carts that occupy the player's lawn.

Terror from Tomorrow
This is the Far Future's Endless Zone. As the player progress throughout the higher levels, the lawn will sometimes give less Power Tiles and machined zombies are most likely to appear at the very beginning of the level. Disco-tron 3000's, Mecha-Football Zombies, and Gargantuar Primes are considered dangerous in this Endless Zone.

Arthur's Challenge
This is Dark Ages' Endless Zone. As the player progresses throughout the higher levels, eighty percent of the lawn will be filled with tombstones, preventing the player from planting plants. Also, from time to time gravestones will rise more frequently, making the surprise attack much frequent that it was. Powerful zombies in this Endless Zone include the Jester Zombie, Wizard Zombie, and Dark Ages Gargantuar.

Tiki Torch-er
This is Big Wave Beach's Endless Zone. As the player progresses throughout the higher levels, the tide line will get closer and closer to the edge of the lawn, forcing the player to use Lily Pad and Tangle Kelp and giving zombies such as the Surfer and Snorkel an advantage by allowing them to stay in the water longer. The tide also changes more often, sometimes surprising the player by swamping his/her plants or summoning powerful zombies via Low Tide. Watch out for Surfer Zombies, Octo Zombies, Fishermen Zombies, and Deep Sea Gargantuars in this Endless Zone.

Vasebreaker Endless
This is the Endless version of Vasebreaker. It is unlocked by beating Boss Vase. Like the first game, Gargantuars are always found in purple vases, makes the level easier. It is highly recommended to prepare that row with heavy defense before the player breaks them. Also the player can use Cherry Bomb like in the first game. When the player reaches to wave 16, he or she unlocks a Power Up called Move Vase.

Trivia

 * Versions 1.0 to 1.6 of Plants vs. Zombies 2: It's About Time does not allow the player to Save and Quit over the course of Endless Zone. The only way is to finish the level then save and exit. Along with this version, power-ups and spending coins for Plant Food can only be used once.
 * In the game files, Endless Zones are called DangerRooms.
 * There is a glitch when the player lose the Endless Zone, then play again without quitting, the player will lose all his or her Lawn Mowers in the 1.9 update. However, this was fixed in later versions.
 * There is a glitch where visiting the Zen Garden before starting a level gives the player access to every seed packet. This can be used to get Blover in Pyramid of Doom and E.M.Peach in Big Bad Butte. The seed packets will disappear once the level ends, therefore plants must still be permanently obtained through cards. However, as of version 2.3.1, this glitch was fixed.
 * If the player visits Zen Garden and has chosen either a Plant Food or Sun on four of the cards, the player will still keep the card they have chosen. In previous versions, upon doing so, the selected card will be nullified. However, as of version 2.4.1 the player will get a chance to keep the Sun or Plant Food card he has selected.
 * This glitch also occurs when force-quitting the game in the Seed Selection screen.
 * As of the 2.7.1 update, the plants that are in the card have costumes too. If the plant does not have a costume then it will be seen as a regular one.
 * There are no Endless Zones in Chinese version.
 * Before the 2.7 update, the player can choose the fourth card without opening it by tapping it first, then tapping one of three first cards, then tapping again the fourth.
 * Out of 12 zombies to fight (11 in Arthur's Challenge), the game will select randomly from five to six zombies that the player will fight in a level (the game selects seven in Big Bad Butte).