Increasing the income in City Go is the major purpose of the game for many players, as a larger stream of income will let you unlock new levels faster.
Merging buildings together to increase their level is one way to increase the overall income of City Go. Players find so many repetitive buildings whenever they roll a die, but these duplicate buildings are actually important, as they can be merged together to create higher-level variants.
How To Merge Buildings In City Go
Open your inventory in the game and look for any building type that you have at least three or more of. Whenever you collect three duplicates of a building, you can click on the upgrade button when inspecting the building and merge it!
This action combines all three duplicates into one building of a higher level. Merging buildings increases the income they grant to the player.
The common buildings like 1/2 or 1/3 are quite easy to upgrade as the player receives a lot of them throughout the game. But leveling up rare buildings is quite time-consuming. However, merging is always a no-brainer.
If you have buildings that are placed on the map, remove them from the map and bring them back to your inventory to merge them.
Merging is also one of the early quests in City Go that rewards the player with three rolls of 1/100 to 1/150 rarity drops. So, you must learn how to merge your buildings sooner or later.