Secret Fish Stick weapon:
In Act I: Shot In The Dark, after separating into two groups and going to the right, you will enter a sewer. At the starting area of the sewer (before going through the archway), shoot the four valves (two on the left side and two on right side) until they start smoking to spawn the Fish Stick weapon. This weapon runs out of ammo quickly. Once it runs out of ammo, your character will drop it. It can only be used again by reloading the chapter and activating the Easter Egg again.
Relic weapons locations:
Search the indicated location to find the corresponding Relic weapon. Relic weapons contain special buffs that make them more effective. You can add additional special features to Relic weapons by upgrading them.
Enforcer Relic (Act 2: Chapter 2): It is near the entrance to the large open world area. When you reach the first locked gate, stop at the cliffs and look left. There is a skull marker to the left in the trees, which is where you will find the first Relic weapon. The Enforcer Relic has a lower rate-of-fire but does increased damage with each shot.
Longshot Relic (Act 2: Chapter 2): While traveling north from your first objective in Chapter 2 (old COG wall), you can see a red wooden building on the right. Go up to the boat house to find the Longshot Relic. The Longshot Relic gives you a second free shot when you perform a Perfect Reload.
Retro Lancer Relic (Act 2: Chapter 4): After going through the old COG wall to the eastern section of the open world area, look to your left (before you reach a frozen pond on your map). Look left for a red skull on a large rock. Go to that area to find the Retro Lancer Relic leaning against a tree. The Retro Lancer Relic has explosive rounds that will air-burst even if you miss.
Torque Bow Relic (Act 2: Chapter 4): When entering the rusted gates that lead to the "Abandoned Mine" side-objective, go up an optional path to your right. The Torque Bow Relic can be found up the path, between to large rocks. The Torque Bow Relic has a faster draw speed, but the arrows do not explode.
Boltok Relic (Act 2: Chapter 4): The Boltok Relic is just left of the Condor Crash Site in the center-east side of the map —- the one that is locked inside a glacier. Look for a red skull on the ice cliff. The Boltok Relic has better all-around handling and fires quicker from the hip.
Boomshot Relic (Act 2: Chapter 4): In the northern section of the map, take the path leading to the "North Comm Tower" objective. Go right to find the Tower Substation. Next to the substation are are two large square objects. Look between them to find the Boomshot Relic. The Boomshot Relic carries 3 shots per magazine.
Dropshot Relic (Act 2: Chapter 4): Go to the far northeastern corner of the map to find a block glacier in the northeast. Look on the east wall of the glacier for a small snowy path that leads to the Dropshot Relic. It is directly east of the northern Old Derrick Site. The Dropshot Relic freezes enemies with a cryo blast instead of exploding.
Gnasher Relic (Act 3: Chapter 1/3): The Gnasher Relic can be found resting against the cliff wall on the edge of the map, north of the Water Tower/Cosmonaut Training Facility. Look for the red skull marker to find it. The Gnasher Relic fires a single powerful slug that is more accurate than the pellets.
Talon Relic (Act 3: Chapter 1/3): Near the Abandoned Airport where you start, just as you exit to the Skiff, look right to see three large Hangars. The Talon Relic is just on the edge of Hangar 1, to your right when you exit the Abandoned Airport. The Talon Relic fires much faster and does more damage after a Perfect Reload.
Claw Relic (Act 3: Chapter 1/3): North of the City Ruins are a series of small domed structures and bridge. On one of these domes is a red skull marker with the Claw Relic nearby. The Claw Relic has better handling and is more accurate on the wind-up.
Snub Relic (Act 3: Chapter 1/3): Follow the northern edge of the map east from the Rocket Hangar entrance. You will eventually see a red skull on the green/white techno walls to mark the location of the Snub Relic. The Snub Relic fires twice per shot.
Markza Relic (Act 3: Chapter 1/3): At the "Pump Station" side-objective, look on the cliffs past the ruined cars, opposite the entrance. There is a red skull marker with the Markza Relic nearby. The Markza Relic can fire in full-auto.
Lancer GL Relic (Act 3: Chapter 1/3): Travel to the tunnel that leads to the Cosmonaut Training Facility. Opposite of the winding tunnels, on the other side, are cliffs held up with pillars. The Lancer GL Relic is on one of these lower pillars. The Lancer GL Relic launches the grenade directly forward, instead of air-bursting.
Hammerburst Relic (Act 3: Chapter 1/3): Near the "City Ruins" side-objective, just east, is a small structure with an open gate and three submerged archways. Enter through the gate to see the red skull, and pulse the area to find the Hammerburst Relic. The Hammerburst Relic fires in longer bursts with each trigger pull when aiming.
Overkill Relic (Act 3: Chapter 1/3): The Overkill Relic is found on a large rock, directly north of the "Bridge Control Station" objective. The Overkill Relic is fully automatic.
Lancer Relic (Act 3: Chapter 3): Just outside the "Cargo Shipwreck" side-objective, look at the back of the ship to see a red skull marker, indicating where the Lancer Relic can be found. The Lancer Relic can stun enemies with a standard melee attack, making them vulnerable to the chainsaw.
Embar Relic (Act 3: Chapter 3): Near the Condor Crash Site in the far southeast corner of the map, close to the "Turntable" objective, the Embar Relic can be found near the wrecked tail of the airplane. It is a little ways away from the crash site itself, but is easy to spot. The Embar Relic has a longer charge but does more damage per shot.
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:
Jameson Shipping Depot (10 points): Unlock during Act 2 of the Campaign.
It's Time We Fight Them Together (10 points): Unlock during Act 2 of the Campaign.
Shock and Awe (10 points): Use Jack's Shock Trap ability to shock 6 enemies at once in Campaign.
Can't Stop, Won't Stop (25 points): Beat 50 Consecutive Waves of Horde (any difficulty).
Perky's Revenge! (10 points): Get a kill with 3 Perks active in Horde.
One, Two, Three Sorties (5 points): Complete all 3 Objectives for Tour of Duty in a day.
Pass the Soap (5 points): Pass through a refuge shower with 3 Hivebusters in the same shower cubicle.
A Mouthful of Boom (10 points): Unlock during Act 1 of the Campaign.
Now I Gotta Get Up Again (10 points): Unlock during Act 1 of the Campaign.
I Was Born in a Crossfire Hurricane (10 points): Use Jack's Flash ability to stun 3 enemies at once in Campaign.
And... He's All Yours (10 points): Unlock during Act 1 of the Campaign.
Not There to Buy a Timeshare (10 points): Unlock during Act 1 of the Campaign.
Back Atcha (10 points): Get a kill with ricochet bullets using Jack's Barrier Ability.
Back on Your Feet, Soldier! (10 points): Use Jack's STIM upgraded ability to revive a DBNO friendly in Campaign.
Pennies from Heaven (10 points): Scavenge supplies from all fallen Condors in Act 2 and Act 3.
Sire, Interrupted (5 points): Kill a Sire while it's kidnapping a teammate (any mode).
BFFs (15 points): Complete a Versus match with a team of four Level 5 Gears Allies.
You've Got a Friend in Me (5 points): Make a new Ally in Gears Allies.
Did We Just Become Best Friends? (10 points): Reach Level 5 with an ally in Gears Allies.
Seriously 5.0 - Chapter 1 (100 points): Insane Campaign, Master Horde & Escape Launch Maps & Characters, 20 Re-ups, General in Tour.
Once More From the Top (20 points): Re-up!
Corporal Punishment (10 points): Reach the rank of Corporal in a Tour of Duty.
Sergeant at Arms (15 points): Reach the rank of Sergeant in Tour of Duty.
LOOTenant (20 points): Reach the rank of Lieutenant in Tour of Duty.
I'm The Captain Now (25 points): Reach the rank of Captain in Tour of Duty.
Generally Awesome (50 points): Reach the rank of General in Tour of Duty.
My Body is Ready (5 points): Complete Boot Camp.
That Old COG Technology (10 points): Unlock during Act 2 of the Campaign.
Let's Get You Some Answers (10 points): Unlock during Act 2 of the Campaign.
We Need the Old Plan (10 points): Unlock during Act 2 of the Campaign.
Safe and Sound (10 points): Unlock during Act 3 of the Campaign.
Cutting it Close (10 points): Unlock during Act 3 of the Campaign.
Throw a Switch, See What Happens (10 points): Unlock during Act 3 of the Campaign.
Let's Keep Pissin it Off! (10 points): Unlock during Act 3 of the Campaign.
Then We Watch Each Other's Back (10 points): Unlock during Act 4 of the Campaign.
You Know I Ain't Going Out Like That (10 points): Unlock during Act 4 of the Campaign.
Discovered the True Threat to Sera (20 points): Complete all Acts of the Campaign (Any difficulty).
A Good Plan, Violently Executed (15 points): Execute 100 Rejects (any mode).
An Enemy Among Us (15 points): Get a kill with a Hijacked Pouncer, Warden, Stump and Elite Hunter in Campaign.
Jack of One Trade (5 points): Complete an Act of the Campaign as playable Jack (any difficulty).
Jack of All Trades (25 points): Acquire all of Jack's Ultimate upgrades in Campaign.
Seraninja (10 points): Use Jack's Cloak ability to cloak and execute 3 enemies before de-cloaking in Campaign.
JACKed Up! (25 points): Fully upgrade Jack's Abilities and Passives in Campaign.
Gimme, Gimme, Gimme (10 points): Use Jack's Fetch ability to acquire each Heavy Weapon in Campaign.
Relic Hunter (10 points): Equip 3 Relic Weapons at one time in Campaign.
Relics of the Past (20 points): Kill an enemy with every Relic Weapon in Campaign.
It Takes Three to Make a Thing Go Right (10 points): Complete an Act of Campaign in 3-player co-op.
Master Escape Artist (20 points): Reach Character Level 15 with Mac, Lahni and Keegan.
Who's Your Escape Main? (10 points): Reach Character Level 15 with a launch Escape Character.
Master of My Domain (25 points): Complete an Escape Hive on each difficulty.
Who You Gonna Call? Hivebusters! (10 points): Complete 5 Escape Hives as each one of Mac, Lahni and Keegan.
Brought a Knife to a Gun Fight (25 points): Complete an Escape Hive without firing a shot on Master Difficulty.
The Three Musketeers (15 points): Inflict 9000 damage in Escape while 3 Ultimate Abilities are active.
On the Razor's Edge (10 points): Get 100 kills while inside Hivebuster Venom.
Compulsive Horder (20 points): Reach Character Level 15 with Kait, JD, Del, Marcus, Fahz and Jack.
Who's Your Horde Main? (10 points): Reach Character Level 15 with a launch Horde Character.
Reduce, Reuse, Recycle (20 points): As Jack, convert one of each weapon to Power using the Forge in Horde.
Withdrawal Symptoms (20 points): As a team, collect Power from all 4 Power Taps within one wave of Horde.
And I'll Form the Head! (10 points): Kill a Boss in Horde while all 5 players have active Ultimate Abilities.
Homegrown Hive (10 points): Complete a Featured community built Escape Hive.
I Made It All By Myself (10 points): Create and publish an Escape Hive.
Beginning of a Beautiful Friendship (5 points): Play a match of Arcade.
One Sec, I'll Be Right Back (10 points): Switch characters in an Arcade match and kill an opponent who previously killed you.
Where's My Product Endorsement Deal? (10 points): Win 5 matches of Arcade.
Grind Season (25 points): Win a Ranked match in each week of a Ranked Season.
My Place in the Machine (5 points): Complete placement matches for a Ranked playlist.
All Aboard the Crazy Train! (25 points): Complete all Acts of the Campaign on Insane.
It's Not Hoarding if Your Stuff is Cool (15 points): Collect all Campaign Collectibles.