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Difficulty levels in Halo

Taken from this movie filmed off a TV screen - quality is what it is. :)

Easy: Your foes cower and fail before your unstoppable onslaught, yet final victory will leave you wanting more.

Normal: Hordes of aliens vie to destroy you, but nerves of steel and a quick trigger finger give you a solid chance to prevail.

Heroic: Your enemies are as numerous as they are ferocious; their attacks are devastating. Survival is not guaranteed.

Legendary: You face opponents who have never known defeat, who laugh in alien tongues at your efforts to survive. This is suicide.