I saw a guy I know do this:
Cleanse mission, with Blood Angels
He placed his first heavy weapons choice, a squad of Devastators in a Rhino,at the nexus of the board, forcing his opponenet to deploy at least 18" away, thus forcing them to "bunch up" near the back of his DZ.
Pretty standard.
THEN, at the beginning of turn 1, that Rhino, instead of seeking an unoccupied table quarter, or a vantage point for his devastators, raced into the teeth of the enemy line, and the Devs. dis-embarked, carrying NO HEAVY WEAPONS. they fired their bolters at a squad of Banshees, killing all but 2.They then assaulted a Defender squad with a star cannon, effectively taking out two units!
Now guys, is this a legal manuver? If so, it is HIDEOUS!!!
`Boss!