Unbroken chain is a sequence of matches with identical chips in a row in one match-3 level. Here is an example of how to make Unbroken Chain of 5 matches with Gold Coins in a row in one match-3 level.
Related posts:
Cradle of Empires: What are the bonuses? How can I get bonuses?
Cradle of Empires: Pyramid
Cradle of Empires: What are the crystals? How can I get more crystals?
Cradle of Empires: What are the chargers? How can I get chargers?
Cradle of Empires: Tips on Solving Timed and Blitz Modes
Cradle of Empires: What are the resources? Why do I need resources?
Cradle of Empires: Level Modes