In Xenoblade Chronicles for the Wii, chain attacks are much more powerful attacks that will help you defeat enemies much quicker.
You’ll know a chain attack is available when you see a blue line between two or three of your party characters. You’ll also see a full flashing blue bar at the top left of your screen.
To perform the chain attack, hit up or down on the d-pad and scroll to chain attack and select it. You’ll then select an art to perform which will start the chain. Your other party members will perform moves automatically.
Keep an eye on the multiplier color, because if you get to continue the chain then you’ll want to perform a move with the same color in order to keep the multiplier going higher. Your teammates don’t always do this however, so it can be difficult to get a high multiplier.