Arrival

Arrival is the tutorial level of Halo 3. It contains no actual gameplay, consisting instead of a tutorial (on lower difficulties) and the game's opening cutscene.

Plot
The Master Chief crashes in the jungle and is subsequently recovered by Sergeant Johnson, the Arbiter and several marines. This level consists of no gameplay(save on Easy and Normal, see above), only a cinematic cutscene.

In Heroic and Legendary the only point in doing this level is because you can not get the Campaign Complete on Heroic/Legendary achievements without doing it. Other than that it is completely pointless on the harder difficulties.

First Cutscene
''{It is a night sky: several bright pinpoints of white light, stars, hang in the center. It's a tranquil forest, with lush forestry and a winding river. Then, Cortana's voice begins whispering in voice-overs.}''

Cortana {V.O.}: "They let me pick, did I ever tell you that? ...choose whichever Spartan I wanted."

{Pause}

Cortana {V.O.}: "You know me. I did my research. Watched as you became the soldier we needed you to be."

''{As the camera pans down, something comes into view. The Prophet of Truth's Dreadnought enters the atmosphere, trailing flames splitting the night sky.}''

Cortana {V.O.}: "Like the others, you were strong and swift and brave. A natural leader."

{The fireball comes nearer, at an oblique angle to the camera.}

Cortana {V.O.}: "But you had something they didn't. Something no one saw, but me."

''{A second, lesser fireball breaks off from the main one. It moves at an oblique angle to the first, which is to say, towards the camera. It moves closer while the first vanishes behind a spray of trees.}''

Cortana {V.O.}: "Can you guess?"

{The object moves even nearer, and its trajectory begins to curve until it is heading directly for the camera.}

Cortana {V.O.}: "Luck."

''{The fireball roars past the camera and smashes into the ground with an earth-shattering impact. For a moment, we can see that the area is a jungle, quiet and peaceful, and now, full of light and sound. Cortana's last words are tinged with humor.}''

Cortana {V.O.}: "Was I wrong?"

{Fade to black}

''{Pan down on the same forest, but now, it's early morning, with the sun streaming through the trees onto the smoking ruin where the object hit ground. In the foreground, an armored gauntlet is visible. In the background, several Marines move around; First Squad. The one in the back wears a Sergeant's cap. The Marines of First Squad anxiously observe an awkwardly raised armored gauntlet. A dread permeates the jungle.}''

Marine #1: "This ain't good."

Marine #2: "Damn. How far did he fall?"

{The Sergeant in the hat turns around and takes a long drag on his cigar.}

Marine #3: "Two kilometers, easy."

''{The Sergeant blows out smoke. It is none other than Sergeant Major Avery J. Johnson.}''

Johnson: "Stay sharp."

''{The Marines move closer to the object. For the first time, we can see that it is the Master Chief. He lies at one end of his own personal crater...the results of falling two kilometers, apparently. The MJOLNIR armor's designer would be proud. Despite the motionlessness of the man inside, the armor is neither scratched nor singed. It lays in an odd position, like a dropped statue; the figure is still and hands raised awkwardly: Master Chief is still and silent. The Marines move closer to the Chief, taking up combat positions. One sits down beside the Spartan and takes out a small computer.}''

Johnson: "Corpsman?"

Marine Corporal: "His armor's locked up. Gel layer could have taken most of the impact."

''{He taps something in on the computer. The Chief's outstretched arms collapse onto his chest. The Marine checks for vital signs. No readings.}''

Marine Corporal: "I don't know, Sergeant Major."

''{Johnson kneels by MC and places a hand on his chest, feeling for breath, or any sign that his friend is alive. After a few seconds, he sighs, reaches back, and pulls Cortana's chip out of the Chief's head.}''

Johnson]: "Radio for VTOL, heavy lift gear. We're not leaving him here."

''{An armored hand reaches up and grabs his wrist. The Chief wakes up.}''

Master Chief: "Yeah. You're not."

{He pushes himself slowly to his feet.}

Johnson: {Gives off a small sigh of relief} "Crazy fool! Why do you always jump? One of these days, you're gonna land on somethin' as stubborn as you are! And I don't do bits and pieces!"

''{The Chief says nothing. Instead, he reaches down and takes Cortana's chip from the Sergeant's hand and lets go of his arm.}''

Johnson: "Where is she, Chief? Where's Cortana?"

{The Chief stares at the data crystal, and for a second, Cortana's face flashes across the screen.}


 * Cortana {V.O.}: "Don't make a girl a promise ... if you know you can't keep it."

'{Johnson gives him a confused look.}

Master Chief: "She stayed behind."

{The Chief inserts the chip into the plugin at the back of his head.}

Johnson: "Corporal, make it quick."

Marine Corporal: "Sorry, sir. {to Master Chief} Your armor's still in partial lockdown."

Gameplay
{NOTE: This sequence only appears if playing on Normal or Easy}

Marine Corporal: "Look up here, sir." Use the rs to look up.

''{The Corporal gives him a red light. It goes green when the Master Chief looks at it.}''

Marine Corporal: "Ok. Now down here. Use rs to look dpen(repeats the process) Good. {To Johnson} He's good to go, Sergeant Major."

Johnson: "Take off the training wheels, Corporal. He's good to go."

Second Cutscene
''{The Chief looks around, taking in his surroundings. Somewhere near him is a familiar sight ... the heat-wave effect of a Covenant Active Camouflage. Johnson gives it a nod. An Elite decloaks, revealing itself to be the Arbiter. The Master Chief moves with fluid grace, brushing aside Johnson and another Marine next to the Arbiter, drawing a Pistol.}''

Johnson: "Chief, wait!"

{The Master Chief jams the sidearm between the mandibles of the Arbiter.}

Johnson: "The Arbiter's with us!"

{The Arbiter glares at the Master Chief, who hesitates to lower his gun.}

Johnson: "Come on now."

{Johnson grabs the Chief's shoulder.}

Johnson: "We got enough to worry about without you two tryin' to kill each other."

''{The Spartan lowers his gun. The Arbiter clacks his mandibles together: a shrug.}''

Arbiter: "Were it so easy."

''{He makes as if to push past the Chief, but the Spartan stands his ground. The Arbiter turns and walks away.}''

Arbiter: "We must go. The Brutes have our scent."

Johnson: {On Easy/Normal} Then they must love the smell of green.

Johnson: {On Heroic} Then they must love the smell of hero.

Johnson: {On Legendary, variant 1}: Then they must love the smell of badass.

Johnson: {On Legendary, variant 2} Then they must love the smell of badass. And I left a little present for you, Arbiter. And I'm walking away. Hahaha!

Johnson: {On Legendary, variant 3} Then they must love the scent of testosterone.

Johnson: {On Legendary, variant 4} They must love the scent of a real man.

Johnson: {On Legendary, variant 5} They must love the smell of Bulgari. Yeah, I'm your own little product placement. I gotta get paid too.

''{He grabs an Assault Rifle from a nearby marine and holds it out to the Chief. Swiftly, the Spartan grabs it by the Pistol Grip.}''

Trivia

 * The name may bear a reference to Halo's predecessor, "Arrival" as it is the name of the first level in Marathon, an earlier Bungie game.
 * Arrival is the first tutorial level in the Halo series not to take place on a human space vessel orbiting a celestial body. Halo: Combat Evolved's very first level was on the UNSC Pillar of Autumn orbiting the Halo mega structure and Halo 2's first level was set on the UNSC MAC defense platform Cairo in a geosynchronous orbit around Earth.
 * Contrary to what players might think, the Master Chief did not land on Earth using just his MJOLNIR armor as protection. At the other end of the crater is a metallic object, suggesting the Chief ripped it out of the Dreadnaught and rode it down to Earth. Also, the metallic object appears to be a balcony or platform of some sort due to the support bracing on one side.
 * It should be noted that in Arrival, re-entry occurs before sunrise, and in the Landfall miniseries, re-entry occurs after sunrise.
 * It seems to be that this level is the shortest level in all of Halo History.
 * Look behind you as soon as you start the level, the above statement can be confirmed that the Master Chief did not use his MJOLNIR armor for the impact protection, rather he used a clear-cut Forerunner door that he used as a shield.