Halo Wars 2

As is tradition in the Halo games, Skulls are back as a collectible in Halo Wars 2. There are fifteen in total and they are awarded for completing specific Primary Objectives, Optional Objectives, or unmarked tasks throughout all of the missions in the game with the exception of the Prologue, The Signal.

Collecting your first Skull will unlock "Alas, poor Yorick!;" collecting half of the Skulls will unlock "Morbid curiosities;" collecting all fifteen will yield "Collecting a dream." Please see below for a text-based guide on how to obtain the Skull(s) for each mission.

Mission 2: A New Enemy

• Skull: Grunt Birthday Party
• How to Unlock: Capture Four of Decimus’ Power Nodes
  • After building your base, four Power Nodes will be shown around the map, indicated by an energy bolt icon. Move your Infantry Units to each of the Nodes to capture them. Make sure to do this before carrying on with the Primary Objective.

Mission 3: Ascension

• Skull: Paintball
• How to Unlock: Destroy the Banished base
  • After building your base, begin building a large army of Hornets and Cyclops. Once you're set, head north, beyond Capture Node B, and you will find the Banished base. Do not capture any of the Capture Nodes until after destroying the base (just so that you are not running against the clock).
• Skull: Pain Train
• How to Unlock: Destroy the hidden facility’s four structures
  • After building your base, take three or four Hornets and move them to the darkened island south of your base. Here, you will find a hidden Banished base with a few Infantry Units. Use your Hornets to destroy the enemies and the four structures of the base.

Mission 4: One Three Zero

• Skull: Bountiful Harvest
• How to Unlock: Don’t let any of the four prison squads die
  • During this mission, Alice will be required to rescue four squads of prisoners, the first half of which are Hellbringers and the second half of which are Warthog Units and Cyclopses. Try to keep the Hellbringers in the rear while you focus on controlling/moving Alice throughout the mission. Once your entire squadron reaches the comms building, move your Hellbringers and Warthogs behind the building. Now move Alice and one Cyclops into one of the two garrisons in front of the building and move the other two Cyclops into the other garrison. Hold out like this until extraction arrives, making sure none of the Cyclops or Units behind the building die.

Mission 5: The Cartographer

• Skull: Emperor
• How to Unlock: Destroy both minibases in the central chamber
  • After powering down and passing through the energy barrier, you may notice that in the northern end of the chamber, on both the eastern and western edges, are Banished minibases. Make sure to destroy both bases before moving on with the Primary Objective.

Mission 6: Lights Out

• Skull: Pestilence
• How to Unlock: Release all 10 UNSC Prisoners
  • You will find your first set of prisoners just north of the mission start. Then, after passing through the portal, you will need to head to the right-hand side of the valley to find three additional cells of prisoners. Make sure to rescue them before moving on with the Primary Objective.

Mission 7: From The Deep

• Skull: Total Annihilation
• How to Unlock: Complete the mission without Spartan Alice being downed
  • The best method to employ for this task is to have Alice either hijack a Wraith on the beach or take control of the Scorpion tank on the beach (either works). Make sure Alice is your primary focus throughout the mission; heal her when needed and make sure she doesn't take the brunt of the enemy's attacks. When the Scarab shows up at the end of the mission, you should already have a sizable army of Scorpion tanks to accompany Alice in taking it down quickly.

Mission 8: Hold The Line

• Skull: Sickness
• How to Unlock: Keep the barricades intact
  • In this mission, you will need to protect the western and eastern barricades; the former of which is just to the left of your base and the latter of which is a little southeast of your base. The best way to ensure they aren't overwhelmed and destroyed is to build one Anti-Infantry and one Anti-Vehicle turret at each barricade and then place at least three or four Hornets just ahead of the barricade as the "first line of defense." It's recommended to try doing this on a low difficulty, as the enemy forces become increasingly difficult to keep at bay past the fifteen minute mark.
• Skull: Hold The Line
• How to Unlock: Particle Cannon stays above 50 percent health
  • If you are successful in keeping both barricades intact for the "Sickness" Skull, then you shouldn't have to worry about this because no enemy Units would have been able to reach the Particle Cannon.

Mission 9: Under The Dark

• Skull: Things That Make You Go Boom
• How to Unlock: Eliminate all three Brute Warlords
  • You will come into contact with the first Warlord by moving your Units past the first base you build and down the ridge to the Banished's base. Provided you stick to the right-hand side of the valley/map once you are in Alice's segment of the mission, you will encounter the second Warlord on your way to the first Kodiak deployment position. The last Warlord can be confronted by continuing to travel north on this eastern edge of the valley; once you reach the second red energy barrier, he will attack you. While the Warlords have a large amount of health, they should be rather easy to kill with Sniper Units and your Spartans.

Mission 10: The Foundry

• Skull: Wuv Woo
• How to Unlock: Keep The Scarab Alive During The Entire Mission
  • Keeping the Scarab alive through the mission shouldn't be too much of an issue if you're playing on one of the lower difficulties. If you're playing on Heroic or Legendary, though, make sure the Scarab stays at the rear of your squad so it doesn't take too much damage. Move slowly at all times and be smart as to when it's necessary to retreat and heal your Units.
• Skull: Sugar Cookies
• How to Unlock: Keep the scarabs health above 25%
  • If you are attempting to unlock the "Wav Woo" Skull in this mission, this will likely mean your Scarab should have no issue staying above 25% of its health. As mentioned, just take the mission and its objectives slowly and keep your Scarab at the rear. Do not rush!

Mission 11: The Halo

• Skull: After Party
• How to Unlock: Rescue Bravo Base
  • When the mission starts, you should notice a Power Node just ahead. Capture that Node and then Captain Cutter will inform you of Bravo Base; they are under attack and need your help. Move your Units to Bravo Base and repel the Banished's assault as quickly as possible.

Mission 12: Last Stand

• Skull: Nightmare
• How to Unlock: Keep the Control Room Shield over 50%
  • Since you do not have access to base-building during this mission, you will need to rely on the Units that Captain Cutter periodically provides. To start, make sure to build and upgrades turrets around the edges of the central chamber. Focus on building Anti-Infantry and Anti-Vehicle turrets. Next, you'll want to make sure each of the four entryways of the chamber are appropriately defended. Split your focuses intelligently; you'll have access to Hellbringers, Snipers, Spartans, Nightingales, Warthogs, Wolverines, Scorpions...you name it. Spread them out evenly and make use of your Leader Powers as often as possible.
• Skull: Shadow
• How to Unlock: Kill the two Brute Warlords and stop their reinforcements
  • Halfway into the mission, you will be informed that Brute Warlords are converging on your position. They will both be displayed on your mini-map, but they don't necessarily storm your position; rather, they will remain far away, under the cover of the Fog of War, with their army of reinforcements. Once you have a sizable and formidable squadron of mixed units (Snipers, Spartans, Scorpions, Cyclopses, etc.), storm each Warlord's position to take them and their reinforcements out. Remember to make use of your Leader Powers and the Spartans' "hijack" ability, too!