Research (BMC)

"You will not easily deal with MOAB-class without some serious power. Tier 4 Monkey upgrades require Special Buildings to unlock. Build a Special Building for an upgrade, then research that in the upgrades menu."

- "Real Power" goal description

Research is the necessary action required for unlocking upgrades in Bloons Monkey City and Bloons Monkey City Mobile. They cost City Cash, and sometimes Bloonstones, and must be researched in an Upgrade Building, with the order of tiers. The lowest tier is researched before the highest in a certain path of a certain tower.

Costs

 * Further information: Buildings 

All research costs City Cash, but some research requires more than this. A certain City Level, Bloonstones and Special Buildings may also be required. Any Special Buildings built will cost City Cash and Power, so think wisely before thinking about unlocking tier-4 upgrade (or a tier-3 Super Monkey upgrade). In BMC Flash, researching tier-3 upgrades costs a sum of City Cash plus 20, while researching tier-4 upgrades costs a sum of City Cash plus 50.