Editing Sierra 117

{{Status|Gameplay}}

|player=*[[Master_Chief_(gameplay)#Halo_3|Master Chief]] (player 1)

*[[Elite (co-op)|Usze 'Taham]] (player 4)

Having been found by [[Sergeant]] [[Avery Johnson]], [[Marcus Stacker]], some [[UNSC Marine Corps|Marines]], and the [[Arbiter]] [[Thel 'Vadam]], the [[John-117|Master Chief]] is escorted through the jungle, not knowing there is trouble ahead. Johnson has with him two squads of Marines, but, after spotting a Covenant [[Ru'swum-pattern Phantom|Phantom]] overhead, he decides to split them in order to attempt to reach an evacuation point at a nearby river. The Master Chief, Thel 'Vadam and one squad head one way, following a stream leading to the river, while Johnson and the other [[United Nations Space Command|UNSC]] forces scale a waterfall, and head another way. Bravo squad, apparently left behind by Johnson's team to guard the Landing Zone, where Pelicans were to extract the troops, breaks radio silence, and is attacked by a [[pack]] of [[Jiralhanae]], led by a [[Jiralhanae Chieftain]].

By the time the Master Chief and Thel 'Vadam make it to the river for evacuation, the [[D77H-TCI Pelican|Pelican]]s at the evacuation point are already under attack by [[Covenant Empire|Covenant]] infantry. Johnson is seen using the [[AIE-486H machine gun|machine gun turret]] at the back of one of the Pelicans, and with combined fire the Covenant are momentarily pushed back. Several [[Type-26 Banshee|Banshees]] swoop in on and attack the Pelicans. Both Pelicans suffer catastrophic wing damage from the Banshees' [[fuel rod cannon]]s and make a fiery exit further down river as more Jiralhanae and Unggoy reinforcements show up to kill Master Chief's squad. After pushing through the Covenant forces, the Chief and Thel 'Vadam are told over the COM that Johnson's Pelican has crash landed and shortly afterward come across him and his squad fleeing from the crash site, pursued by Jiralhanae and Unggoy forces. The Chieftain pulls his own Phantom out of the fight to regroup.

They desperately try to catch up with Johnson, killing many Unggoy, Jiralhanae and [[Kig-Yar]]. After coming across the crashed Pelican, they find [[SRS99D-S2 AM sniper rifle|Sniper Rifle]]s and [[BR55HB SR Battle Rifle|Battle Rifle]]s. Master Chief, Thel 'Vadam and the surviving marines then find themselves in a thick jungle and have to fight past Kig-Yar hiding in the trees and on the ground, with no sign of Johnson or his squad of marines.

They then reach a large dam where they see Johnson being taunted and kicked into a small building and held captive by a Jiralhanae Chieftain. It is implied that this is the same Chieftain that killed Bravo's men and pursued Johnson from his crash site. The area is also littered with Unggoy and Kig-Yar as well as half a dozen Jiralhanae. With slow progress, the two heroes manage to fight their way through and around the dam and eventually take down the Jiralhanae Chieftain. They then rescue Johnson and the three surviving marines from his squad. (Note: the marines will be dead if you still have marines from before)

Johnson calls in Pelican [[Kilo 023]] piloted by [[Hocus]] to come and pick them up, but they are first engaged by two Phantoms which drop off hordes of Unggoy and a few [[Jiralhanae Captain]]s wielding [[Type-25 Brute Shot|brute shot]]s and [[Paegaas Workshop Spiker|spiker]]s. Whilst the group engages the ground forces, the Pelican arrives and takes down the two Phantoms with missiles. Hocus then lands and evacuates the survivors and Johnson is seen patting the Chief on the shoulder in thanks before the Pelican flies off.

*''(2-Player Co-op Change)'' '''Sergeant Johnson''': "First Squad, you're my scouts. Arbiter, watch the Chief's back. Move out! Quiet as you can."

*'''Sergeant Reynolds (COM)''': "Johnson, you be advised. Hostiles are -''{static}''- on the move -''{static}''-. I've got eyes on a -''{static}''- Brute [[Pack]] -''{static}''-. Over."

*'''Sergeant Johnson''': "Say again, [[UNSC rank structure|Gunny]]? You're breaking up."

''There is the ominous whisper of gravitational drives as a [[Ru'swum-pattern Phantom|Phantom]] flies overhead above the trees.''

[[File:H3 Sierra117 Marines.jpg|thumb|300px|John-117 follows First squad to the river for pickup.]]

''After advancing through the caves, the team enters a massive forested expanse and finds the "Grunt Camp".<ref name="official guide">''[[Halo 3: The Official Guide]]''</ref> Sleeping Unggoy litter the first half while a few Jiralhanae, [[Kig-Yar]] and other Unggoy patrol the far hills.''

''First Squad leaves the caves; the river is around the next bend. Three Marine corpses are scattered on the ground, with [[BR55HB SR Battle Rifle]] ammunition and [[M9 fragmentation grenade|Fragmentation Grenade]]s.''

''As the Master Chief and his allies take out the Covenant forces that are closest to the Pelicans, two [[Type-26 Banshee|Banshee]]s streak in along the river.''

''The Chief and 'Vadam encounter many hostiles, including a Jiralhanae Chieftain on the side of a Phantom, who flies off when either his gunner or many of his troops are eliminated. The Chief and 'Vadam secure the area, and discover Echo 51's crash site by the riverside.  The crashed dropship, lying on an outcropping along the valley wall, is surrounded by [[MA5C assault rifle|assault rifle]]s, [[BR55HB SR|battle rifle]]s, a [[SRS99D-S2 AM|sniper rifle]], ammunition, and Fragmentation Grenades. The Pelican's radio is still operational.''

''Two Phantoms arrive, carrying reinforcements. The Chief, 'Vadam, Johnson and any accompanying Marines engage the newly-arrived Covenant troops. The Phantoms hover over the river, their Unggoy gunners opening fire with their [[Pek-pattern plasma cannon|plasma turret]]s.''

*All of the kills Hocus gains through her missiles are headshots. This can be seen by turning on the [[Halo_3_skulls#Grunt_Birthday_Party|Grunt Birthday Party skull]] and leaving some grunts alive at the bridge, then quickly rushing to the bridge (note that the player is not supposed to actually try to kill them, due to her missiles being able to kill the player.) When her missiles kill the [[Grunts]], one can easily see the confetti and hear the children laughter.

*The [[Arbiter eye glitch]] can been seen on this level, if paused in Theater mode right at the start of the level before the game goes to full screen.

*In [[Theater]], it is possible to see a six-winged bird. At the start, when the player sees the first Brute, three birds will sometimes fly low through the area and get stuck on the rock that the Brute is standing on, overlapping and forming a six-winged bird. It will disappear in a few seconds, so one may have to view the level in the [[Theater]] and pause when one sees it to get a good look at it.

*There are two [[vacation]]s that can be performed in this level. (See: [[Sierra 117 vacation]].)

*It is possible to "break" the level by tossing a [[Anskum-pattern plasma grenade|Plasma Grenade]] at [[Kilo 23 (Pelican)|Kilo 23]]'s cockpit at the end of the level. The grenade will pass through the door to the cockpit and kill [[Hocus]], causing the [[D77-TC Pelican]] to fall through the level's geometry and disappear. Caution: Kilo 23 is rather large. if it falls on you, you may be splattered.

*If, during the ''Charlie Foxtrot'' chapter, you shoot Johnson off of the bridge as he crosses it, he will begin to fight the [[Unggoy|Grunts]], and if you are playing on a sufficient difficulty (Legendary with a few gold skulls on), he can be knocked back by grenades and Brute Shot blasts. On rare occasions, he will be held back and rejoin your group, and on other occasions, he may get "stuck" against an environmental obstacle, able to move but refusing to do so. When you go to the bottleneck of the forest before the [[Brute Chieftain]] locks Johnson in the room, he will vanish. If done correctly, when you look at Johnson being held by the chieftain, he will be running and wielding his rifle.

*When playing on [[Heroic]] or [[Legendary]], you can use a glitch to get the [[Type-1 energy sword|Energy Sword]] that Thel 'Vadam wields. Deliberately weaken the Arbiter by destroying his shield. Either make sure you see his Energy Sword on his hips, or when near enemies, he'll take it out. Kill him by either sticking him with a Plasma Grenade or letting the Covenant kill him (though the latter method will make it harder to find 'Vadam's corpse and his Energy Sword). When the deed is done, pick up the sword and it'll have around one to five energy left. If you want a fully-charged '''Energy Sword''', repeat the steps again, but wait several seconds after 'Vadam respawns, or he will see you as a [[Treason|traitor]], and kill you with one shot or melee attack.

*In the area where the two Pelicans are shot down by Banshees, as you head back into the jungle, you may be able to grenade the Arbiter off the cliff and onto the waterfall. He will slide down into the water, some distance beneath the surface, and run around for a little while. If you fire at him, you may be able to hear him faintly utter the usual phrases (e.x. "Save your fire for the Brutes!"). He will typically head off to the right (your right, when facing the entrance to the jungle) and travel some distance before reappearing back on the cliff, blindly running into a wall until you approach him.

*At the end of the level, you can shake Hocus's Pelican. To do this, you'll need the [[Gravity hammer (fiction)|Gravity Hammer]] and possibly some Plasma Grenades. Jump on top of the Pelican once it comes to pick you up, by using the ledge to the left of it. Whack the tail end with the Gravity Hammer, or throw Plasma Grenades at it, making sure it moves away from the bridge. If done properly, the Pelican should move around.

===Easter eggs===

{{Main|Easter egg}}

*Near the end of the level, you can use the [[elevator glitch]] where the skull is located to get on top of the glass structure. If you walk across the structure and proceed onto the side of the cliff you will be able to find a lone caveman, which is similar to the cavemen you can find at the beginning of the level.

*You can also use the Elevator glitch to get onto the platform above the Skull. You will need the chieftain's Gravity Hammer to get up. Once you are up, get your co-op pal to commit suicide. They should respawn above the player on the ledge above the skull. Once you have beaten the map, you can wander around above the dam and up into the hills on foot. There are numerous features like small hills and large holes in the ground. It has yet to be fully explored.

*If player one takes too long to board Hocus's Pelican at the end of the level, Johnson might say, "Come on, Chief! The fight isn't gonna' finish itself!" This is an obvious reference to the ''[[Halo 3]]'' tagline, "Finish the fight!".

*There are invisible floors on this level that make it seem like you are walking the stairway to Heaven. To do this, just use the Elevator glitch to get out of the map near the dam area by the Iron Skull.

*The Achievement "Landfall" is the same name as the Halo Shorts Series, ''[[Halo: Landfall]]''.

File:Concept-H3-Sierra-Kilimanjaro.jpg|Concept art of John-117 with a Pelican and Mount Kilimanjaro in the background.

File:H3 KilimanjaroConcept.jpg|More concept art of Mount Kilimanjaro.

File:H3 Dam concept.jpg|An early sketch of the dam.

File:H3 HydroConcept.jpg|Early concept art of the [[A2 Hydroelectric Facility]].

File:H3_A2Hydro_Concept_1.jpg|Concept art of the hydroelectric facility.

File:H3_A2Hydro_Concept_2.jpg|Another concept of the facility.