Locked and Loaded is a Brain Buster in Plants vs. Zombies 2 and Plants vs. Zombies Online where the player has to use the pre-selected plants given to them to defeat the zombies. Before the 1.7 update, it was unlocked with four keys in Ancient Egypt and Pirate Seas, and five keys in Wild West. The player would receive a star after completing a level without losing any lawn mowers, though that was not a requirement after beating the level. After the 1.7 update, Locked and Loaded levels are placed like other level on the revised map, but have the requirements regardless of the number of times played. In addition, they are no longer referred to as "Locked and Loaded"; instead, they are named like other levels, and each world had a Locked and Loaded level removed. In the 1.9 update, the game removed the requirement on all levels with objectives to not lose any lawn mowers, including Locked and Loaded levels.
If a plant is leveled up and is present in a Locked and Loaded level, it will not be given at level one, but can be given a level increase when in a "Try a leveled up X" level.
The Roman numerals are the level numbers before the 1.7 update for Ancient Egypt, Pirate Seas, and Wild West, but is used for disambiguation purposes for the remaining worlds. The parentheses show where the level is located after the 1.7 update, or if the level is removed in the update altogether.
The selection of plants often includes one or more plants that the player has not yet unlocked.
Lost City has the most Locked and Loaded levels of any world so far, with six.
However, after the Jurassic Marsh expansion, with two new Locked and Loaded levels (Day 34 and 38), Jurassic Marsh is tied with Lost City for the most Locked and Loaded levels of any world.
The first level of the first three worlds' Locked and Loaded levels feature the last plant unlocked with it (Twin Sunflower, Cherry Bomb, and Winter Melon).
Not counting Piñata Parties and Penny's Pursuit levels, Pirate Seas - Day 18, Frostbite Caves - Day 14, Lost City - Day 8, and Neon Mixtape Tour - Day 9 are the only Locked and Loaded levels without selected sun-producing plants. However, Frostbite Caves - Day 14 and Neon Mixtape Tour - Day 9 have pre-placed Sunflowers, while Lost City - Day 8 has Gold Tiles which produce sun.
Lost City - Day 8 and Neon Mixtape Tour - Day 9 are the only Locked and Loaded levels to have an extra objective.
Wild West - Day 28 is the only Locked and Loaded level to give two plants, the least so far.
Specific to Plants vs Zombies 2 (Chinese version) (China only)[]
(pre-8.9)
(imitates 
