Progress through the game until you can hire new soliders. Then, go to the Barracks, and select the "View Soldiers" option. Choose a soldier, then select the "Customize" option. This can also be done from the "Customize" menu at the "Deploy" screen. Change the name of the soldier to one of the following names to unlock the corresponding hero. These new heroes will dramatically improve the unit's stats, and they also have a unique nickname. Note: Using these special heroes will prevent achievements from being earned.
Chris Kluwe: Enter "Chris Kluwe" as a name. Chris Kluwe is a punter for the Minnesota Vikings and a World Of Warcraft fan. He won hero unit privileges after defeating Firaxis' Garth DeAngelis in an online match.
Joe Kelly (Heavy): Enter "Joe Kelly" as a name. Joe Kelly is a popular comics author that has worked on Spider-Man, Superman, and many other famous characters.
Ken Levine (Sniper): Enter "Ken Levine" as a name. Ken Levine is the co-founder of Irrational Games, the developer of BioShock, Freedom Force, and System Shock 2.
Otto Zander (Assault): Enter "Otto Zander" as a name. Otto Zander is the hero and survivor of GuavaMoment's XCOM Let's Play series from the Something Awful Forumes.
Sid Meier (Support): Enter "Sid Meier" as a name. Sid Meier is the co-founder of Firaxis and creator of the Civilization series, Pirates series, and more.
William Carter: Enter "William Carter" as a name. William Carter is the lead character in The Bureau: XCOM Declassified. He will also be wearing his 1950s fedora.
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:
- Who Needs Limbs? (20 points): Augment a soldier in single player.
- A Little Bit Alien (20 points): Modify a soldier in single player.
- Enemy Within (20 points): Get a Soldier to have 5 modifications in single player.
- Steel Martyr (40 points): Deploy three tactical subsystems on a single soldier in single player.
- Apotheosis Denied (100 points): Deal with the newest global threat.
- They Shall Not Pass (20 points): Eliminate all alien waves.
- Zom-B-Gone (20 points): Eradicate the infestation.
- An Army Of Four (100 points): Beat the game without buying a Squad Size upgrade (Classic+ difficulty).
- The Meld Squad (20 points): Field a fully enhanced squad and win the mission.
- Shieldbuster (20 points): Eliminate an enemy's shield and kill it on the same turn in single player.
- Someone Your Own Size (20 points): Kill a Muton Berserker in melee combat in single player.
- Taking A Load Off (20 points): Stop a squad member from suffocating in single player.
- Where in the World (40 points): Make certain of the new threat's location.
- Mind the Step (20 points): Jump two stories in one move in single player.
- Nice Cover (20 points): Use Collateral Damage to blow up a car in single player.
- By Our Powers Combined (40 points): Field a squad with 4 augmented soldiers, each with a different base ability and win the mission.
- Rise of the Machines (20 points): Field a squad consisting entirely of augmented soldiers and SHIVs (min. 4) and win the mission.
- Mutatis Mutandis (20 points): Field a squad where all members have at least two modifications (min. 4) and win the mission.
- Mental Minefield (40 points): Kill an enemy as it is psionically attacking you in single player.
- Anger Management (20 points): Proc Combat Rush on the entire squad (min. 4).
- Remington... Max Remington (40 points): Have your special-duty soldier kill three enemies in the same mission.
- G'day (20 points): Kill an elite enemy Sniper with one of your own snipers in single player.
- Regenerate This (20 points): Kill an elite enemy Medic with explosive damage in single player.
- Tingling Sensation (40 points): Kill an unseen enemy detected by a specially modified soldier in single player.
- Pain in the Neck (40 points): Cause an enemy to suicide.
- Solid Prospect (20 points): Complete Deluge.
- Ours are the Furies (20 points): Complete Furies.
- Elite Defense (40 points): Beat a new special mission without losing any assets.
- Guardian of Earth (100 points): Designate a highly decorated soldier as the Volunteer.
- All Hands On Deck (20 points): Get at least 4 kills with XCOM Base Security personnel.