Like an American pale ale with more body, more caramel richness, and a balance more towards malt than hops (although hop rates can be significant).
Can overlap in color with American pale ales. However, American amber ales differ from American pale ales not only by being usually darker in color, but also by having more caramel flavor, more body, and usually being balanced more evenly between malt and bitterness. Should not have a strong chocolate or roast character that might suggest an American brown ale (although small amounts are OK).
North Coast Red Seal Ale, Tröegs HopBack Amber Ale, Deschutes Cinder Cone Red, Pyramid Broken Rake, St. Rogue Red Ale, Anderson Valley Boont Amber Ale, Lagunitas Censored Ale, Avery Redpoint Ale, McNeill's Firehouse Amber Ale, Mendocino Red Tail Ale, Bell's Amber
You can view the complete style details on the BJCP website. The 2008 style guide is obsolete but there is a similar 2015 style that you can view below...