Key


 * Not to be confused with World Key from the International version.

Key is an item in the Chinese version of Plants vs. Zombies 2: It's About Time and in Plants vs. Zombies Online. The player needs them to open gates to get upgrades and plants and to unlock Brain Busters. There are different variations of keys for each world. However, in Plants vs. Zombies Online, they are all the same.

Keys were also originally in the international version of Plants vs. Zombies 2: It's About Time, but were removed in the 1.7 update, as a new method of unlocking plants and rewards replaced the original layout. Any keys the player had before the update were turned into coins. World progression now takes place through the use of World Keys obtained by defeating the Gargantuar level for the first time in any world.

How to obtain
Keys are found as a rare drop off of all zombies killed in a time zone. The odds of a zombie dropping a key are relatively low, around one percent off of any zombie, regardless of health or speed. Keys could also be found off of the Treasure Yeti every once in a while, and a lunchbox can carry three keys of the area the Yeti was killed in. Finally, Piñata Party piñatas had a chance to carry one key for any area, as long as they player had that area unlocked.

Collecting keys

 * Killing the Treasure Yeti was one of the best ways to get keys, as every other lunchbox has three keys.
 * Playing levels with a high zombie density provided more chances for keys to drop.
 * Completing Piñata Parties could have resulted in a few keys being rewarded.
 * Zombie strength does not effect drop chances, so it was more practical to battle large amounts of weaker zombies for key farming.

Trivia

 * Each gate involved three to five keys to be unlocked, except for the Special Delivery gate in Ancient Egypt, which involved one key.
 * As of the 1.7 update in the international version, the player's previous keys (if any) have been turned into coins, because there is no need for them anymore.
 * Keys max out at 99; any more collected will not increase the counter past the maximum.