The Sims 4 has revamped item collection from The Sims 3, making it a larger aspect of the game, and linking various Aspirations to it. There are currently 13 collections in the base game, three additional collections temporarily added with from patches, one additional collection added with Outdoor Retreat, one additional collection added with Get to Work, one additional collection added with Dine Out, one additional collection added with Kids Room Stuff, and two additional collections added with City Living. Collecting is not a skill that Sims can develop.
There are various rocks scattered around neighborhoods, that Sims can dig in order to gain metals, crystals, MySims trophies, and fossils. Frogs can be collected by searching from fishing spots, that can be found in Magnolia Blossom Park and Desert Bloom Park, or from moss-covered logs. The Curator aspiration is heavily focused on collecting, with milestones requirements having things such as collecting crystals, frogs and fossils.
Players can track the number of collectibles the household has collected by the usage of the Household Collections, that can be found from the upper right corner of a Sims inventory, indicated by a diamond.
Sims with the Appraiser aspiration reward trait can sell collectibles such as, metals, crystals, elements, and fossils to the Simsonian Museum for extra money.
List of collections
There are 10 Aliens that can be collected, and they are collected through Space Exploration on a Rocket Ship.
There are 20 Crystals that can be collected, and they are collected through exploring various Rocks in the world.
There are 15 Elements that can be collected, and they are collected through sending Crystals and Metals to the Geo Council.
There are 22 types of fish that can be collected (27 with Outdoor Retreat), and they are collected through fishing at various places in the world.
There are 15 Fossils that can be collected, and they are collected through exploring various Rocks in the world.
There are 25 Frogs that can be collected, and they are collected in Logs, Ponds, or farmed through Breeding.
There are 32 Plants that can be collected, (42 with Outdoor Retreat) and they are collected through finding them in the wild or Grafting them together to earn rare specimens.
There are 20 Metals that can be collected, and they are collected through exploring various Rocks in the world.
There are 12 Microscope Prints that can be collected, and they are collected through Analyzing Plant/Fossil Samples on a Microscope.
There are 20 MySims Trophies that can be collected, and they are collected through exploring Rocks in the world, then finding a capsule. Opening it grants a MySims trophy.
There are 14 Postcards that can be collected, and they are earned through getting Pen Pals, and talking with them enough to ask for a postcard that is received in the mail.
There are 15 Space Prints to be collected, and they are earned through Stargazing/Observing the Sky using the Observatory.
There are 4 Space Rocks to be collected, and they are collected through Space Exploration on a Rocket Ship.
There are 10 Decorative Eggs to be collected. This collection was introduced in patch 15, and until patch 17 the "Bunny Egg Hunt" challenge could be collected through harvesting plants, collecting mail, opening capsules found by excavating rocks, and looking in logs. Completing this collection unlocks a giant stuffed bunny.
There are 9 Sugar Skulls to be collected. This collection was introduced in the patch 41, and until the "Day of the Dead" challenge could be collected by asking Day of the Dead celebrators. Completing this collection will allow Sims to use the "Honor the Dead" interaction, granting them the "Day of the Dead Celebrant" moodlet which will boost interactions with the Grim Reaper.
There are 6 Magic Beans to be collected. This collection was added in the patch 49, and until the "PlantSim" challenge could be collected by asking various PlantSims.
There are 21 insects to collect, and they are found by searching for them in Granite Falls.
Get to Work
There are 6 Geodes to collect, and are found on Sixam. They can be found either via leveling Rocket Science to 10 and upgrading the rocket to enter wormholes, or reaching a high level in the Scientist career.
Experimental Food Prints
There are 20 Experimental Food Prints to be collected, and can be obtained by taking pictures of different experimental foods, that are found from various restaurants.
Kids Room Stuff
There are 20 Voidcritter cards to collect. Children can find them through a new interaction exclusive to Kids Room Stuff. This interaction allows children to search through trash for the collectibles. Alternatively, they can be purchased from a computer or children can trade them with other Sims. These cards come in booster packs.
There are 15 City Posters to collect. They can be found on the back of electrical boxes that are scattered throughout San Myshuno. Additionally, posters can be found in boxes on the streets.