Call of Duty: Advanced Warfare

In order to earn the trophy, you have to complete the first 24 waves and enter into wave 25 for it to unlock. The game is increasingly more difficult depending on how many people are in your group and how much you communicate. If you're try to survive until wave 25 then I highly recommend either the Cel-3 Cauterizer or the S-12 Shotguns upgraded as soon as you can.

Some other survival tips to keep in mind:

• Avoid narrow areas where you can become easily trapped.
• After you have your Exo, boost as soon as you get hit even one time. You can only take two hits before you are downed without the Exo Health Upgrade.
• Upgrade your shotgun or other burst damage weapon as soon as possible.
• Solo, the Exo Medic upgrade allows you to self revive.
• When purchasing upgrades for your Exo; Exo Upgrade Health, Medic, Reload, and Soldier in that order. When you are downed and bleeding out, your Exo Upgrades will slowly begin to be lost starting with the last one you purchased. If you lose your health upgrade, it becomes a lot harder to survive anything past wave 10.
• Be sure to communicate with your group and pay attention to Power Bonuses as they appear on your screen. These could definitely the tide of any wave.
• Note that you receive one grenade of each type that you carry after completing each round.
• Remember to pick up care packages dropped throughout the match. Save Camouflage as a last resort for reviving a downed teammate or getting out of a bad situation alive.
• Alternatively, there is currently an easy method to earn this trophy that has been posted by StayPationt. This method provides the easiest way make it to wave 25 solo without running the very real risk of dying. The method is detailed in the video below and can only be done in Local Play mode and only on Playstation 4. This exploit does not work online.

PS4

As of Patch 1.14 (March 11, 2015) - The TV exploit location has been patched and no longer works. The grate method in the holding cells is still accessible, though harder to enter.

The video below starts when I obtain the Exo on version 1.14 of the game. I went over the the TV location showing that it no longer works in this patch and I ran toward the grate in the holding cells. In the video you can see that I jump up and boost towards the grate. This is the only way to get into that spot. You'll want to aim at the right edge of the grate itself to get stuck in a solid position. Facing outward, the upgrade station for 20/20 is in the room to your left. You'll have to crouch and jump or sprint to get out of the grate spot. It's best if you try to leave a zombie alive between waves because it can be difficult to reenter the grate spot.

PS3

• There is currently no video for the Playstation 3 spot in order to take advantage of the zombie pile up. After you head unlock your Exo, go back to the administration room. This is the room where you decontaminate during the infected waves. In the room with the upgrade machine, turn directly around while facing it head on and you'll see a TV monitor mounted on the wall. This TV does not exist on Playstation 4 in a way that it can be jumped on. However, on PS3 you can jump and crouch in the air to get on top of this TV. The glitch works the same way as it does on PS4 and it's in the same general area.

This method can also be used to earn 20/20, Moneybags, and PC Load Letter.