Resources are the most important aspect of Backyard Monsters, essential in expansion, construction and protection of the player's yard. Most of these resources can be thrown by a Catapult when attacking another player's yard.
Overworld resources[]
In the game, there are five available resources:
Twigs[]
Produced in Twig Snappers, Twigs are mainly used for constructing and upgradingbuildings. Also used for Twig Missiles in the Catapult.
Pebbles[]
Produced in Pebble Shiners, Pebbles are mainly used for constructing and upgrading buildings. Also used for Pebble Bombs in the Catapult.
Putty[]
Produced in Putty Squishers, Putty is mainly used for unlocking, upgrading and researching monsters, but is also used for attacking and the construction and upgrading of certain defensive buildings. it is also used for Putty Rage in the Catapult. It is also used to transfer monsters to bunkers (The amount of putty needed to put a monster into a bunker is the amount of goo the monster costs divided by two).
Goo[]
Produced in Goo Factories, Goo is used for the production of new monsters. It is the only overworld (non-Inferno) resource which cannot be used in the Catapult.
A way of giving yourself a bonus percentage of your existing Goo (or Magma in the inferno) is when you are upgrading monsters in the Academy. Often, when a monster is upgraded, their Goo value increases. In this case, you can fill your Hatchery with the monster you are upgrading, then cancel them all (or send them to your level 3 Monster Juicer) when the research is complete.
For example, 100 level 1 DAVEs will cost 15 million Goo. After upgrading them to level 2, they will be worth 22.5 million, giving you a bonus 7.5 million if you recycle them all.
Shiny[]
Bought with real money, Shiny allows you to speed things up, buy extra resources, and other nifty things. Posessing Shiny is not essential for playing. There are no essential buildings which can be bought only with Shiny. Gameplay is just as fun with little Shiny (or none at all) it just takes longer. The only other way you can obtain Shiny apart from buying it is by completing some rare quests, once in a Halloween event and finding it beneath mushrooms, which workers can pick in the yard. At the start of the game, you are given 1000 Shiny.
Inferno Resources[]
There are four resources encountered in Inferno:
Bone[]
Produced in Bone Crunchers, Bone is the counterpart of Twigs and is used for constructing and upgrading buildings.
Coal[]
Produced in Coal Extractors, Coal is the counterpart of Pebbles and is used in the construction and upgrading of buildings.
Sulfur[]
Produced in Sulfur Swirlers, Sulfur is the counterpart of Putty and is mainly used for unlocking and upgrading monsters, but is also used for the construction and upgrading of most defensive buildings (except blocks).
Magma[]
Produced in Magma Pumps, Magma the counterpart of Goo and is used for the production of new monsters.

Low level inferno harvester banking balls of resources, from left to right: Magma, Sulfur, Bone, Coal.
Storing resources[]
Resources are initially stored inside the resource building in which they are produced, until they are 'banked' into the yard's storage. The amount of resources you can keep inside your Resource Harvesters or Storage Silos/Resource Pods is determined by the level of each of these individual buildings.
Protecting Resources[]
Protecting Resources is also very important because if your Resource Harvester get destroyed, you lose all the resources in that harvester. If it is less than half damaged, the Resource Harvester will still produce resources (but can't be banked unless you click "Bank all" on another Resource Harvester or it is fully repaired. Put Booby Traps/Heavy Traps around the area where you think monsters will go to get to it.
Trivia[]
- In the early days of BYM, resources used to roll into the Town Hall when banked.