What makes a good multiplayer level?

Back in the early 2000s, when the kings of multiplayer shooters were Quake III Arena and Unreal Tournament, there was a site hosted by GameSpy’s PlanetUnreal.com called CliffyB’s 0wnage. CliffyB is also known as Cliff Bleszinski, lead designer of the Unreal series, and his site was dedicated to reviewing some of the thousands of custom Unreal Tournament maps released by map designers (a.k.a. “mappers"). Map design in Unreal Tournament was one of the game’s greatest strengths, and for a custom map to receive the blessing of none other than the creator of the game was every mapper’s dream. One…