Buildings

Buildings (gold producing structures) are the main source of passive income in the game. They generate gold over time. Each building has its own GPS (Gold per Second). And your global gold production depends on how much buildings of every type you have. Gold production can be further boosted by numerous researches, upgrades, global skills and amulets.

14 types of buildings are currently available in the game. Only 6 of them (Gold pan, Sluice box, Pick, Rocker, Trolley and Dredge) are available from the very beginning. Other 4 buildings (Mine, Pit, Cyborg plant and Alchemist hut) can be unlocked by completing challenges.

Buildings Researches
All buildings except the very first one (Gold pan) should be researched to appear in the buildings menu and become available for purchase. Initial cost of a building research is the same as a basic building cost and you should have at least half of this amount in bank (which means on hand) for the research to become visible. Once the research appears under researches tab it will stay there even if you spend some gold on other buildings/upgrades.

For example Sluice box costs 60 gold. It means that initial price of Sluice box is also 60 gold and you should have at least 30 gold to reveal it under researches tab.

Cost Progression
Every next building is 20 percent more expensive than previous one by default. This multiplier can be reduced by the Cheaper Buildings global skill. or sale hero skill

So the logic behind building's price is following:


 * $$\text {Price} = \text {Base cost} \times M^N$$
 * where M is price multiplier. 1.2 (20 percent) by default. Can be reduced down to 1.15 (15 percent) by Cheaper Buildings global skill.
 * N is number of buildings already owned.

Price always rounds up to the nearest positive integer.

Science
Buildings are very tightly tied with science. In fact every research either unlocks the building or updates its gold production/special ability.

Production researches
Currently there are 6 levels of production researches for every type of building and 5 unlockable by buying an hero skill called hero multiplier. Each level of production research multiplies building's base production by the certain number. For example first level of production research multiplies building's base production by 2, second level by 3, third level by 4 and so on. These multipliers stack, so result multiplier will be:


 * $$2 \times 3 \times 4 \times 5 \times 6 \times 7 = 5040$$

Next level of production research becomes available at the certain number of purchased buildings of this type:

Special ability researches
Unlike production researches, special abilities are unique for every building. They can do literally anything from increasing GPS and GPC to shortening researches time.

There are 5 levels of special ability researches and 5 unlockable with an hero skill called hero special. Availability of the next level also depends on the number of purchased buildings of this type: As you can see, the formula for determining when you can get the next level of a building's special research is as follows: A(sub n) = A(sub n-1) + [A(sub n-1) + 5], where A is the number, n is the level of the skill wanted, and A(sub 1) is 15.