Keys were items in Plants vs. Zombies 2: It's About Time. The player needed them to open gates to get boosts and plants, and to unlock Brain Busters. There were different variations of keys for each world.
Keys were removed in the 1.7 update to Plants vs. Zombies 2: It's About Time as a new method of unlocking plants and rewards replaced the original layout. Any keys the player had before the update will be turned into coins.
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.
- Killing the Treasure Yeti is one of the best ways to get keys, as every other lunchbox has three keys.
- Playing levels with a high zombie density provides more chances for keys to drop.
- Completing Pinata Parties can result in a few keys being rewarded.
- Zombie strength does not effect drop chances, so it is more practical to battle large amounts of weaker zombies for key farming.
- Each gate involves 3 to 5 keys to be unlocked, except for the Special Delivery gate in Ancient Egypt, which involves 1.
- As of update 1.7, the player's previous Keys (if any) have been turned into coins, because there is no need for them anymore.