The Hot Air Balloon is an invulnerable, attack-less exploration unit that hovers above the ground.
There are two types of balloons :
Through the use of the Colonial Age card Hot Air Balloons available to European nations, a player's Explorer gains the ability to release Hot Air Balloons. These balloons will remain active for 20 seconds, and can only be used once a minute, but may be called out an unlimited number of times.
The Industrial Age card Advanced Balloon available to European nations spawns an Advanced Hot Air Balloon at the Home City gather point. This balloon remains active permanently. It cannot be sent a second time upon reaching the Imperial Age.
The Advanced Hot Air Balloon is slower (2.0) and has a smaller Line of Sight (34) than the Hot Air Balloon (3.0 and 44).
They cannot attack and it cannot be shot down. There is no effective counter for the use of balloons with the exception of downing the enemy explorer as often as possible
Hot Air Balloons can be dropped on any area of the map instantly; it does not have to be a location near the Explorer. This means it does not have to fly over enemy walls; it can appear behind them and then begin scouting.
Balloons are capable of capturing herdable animals, or stealing them from the enemy if undefended.
"Joseph and Etienne Montgolfier are to hot air balloons what Orville and Wilbur Wright are to airplanes. They believed that their balloons were held aloft by smoke, burning hay and even shoes to keep early balloons up. Within just a few years, balloons appeared on the battlefield to scout and observe enemy movements and deployments."