Call of Duty: Black Ops 4

Pretty simple to do and easiest in Solo. I recommend playing as the Berserker as the Hammer is a fantastic weapon. This can be done on Casual difficulty. This can not be done in custom games.

The idea of this is to get to round 20 without opening any doors. It sounds hard but it's pretty easy.

First activate a banner challenge on round 1. To do this, go to one of the four rolled up banners around the arena and knife the rope next to it. This will unroll the banner and give you a series of challenges.

When you do one, turn it in at the podium in the middle of the arena. Complete 3 challenges and you'll get a PaP Pistol. This pistol is an absolute machine and will make your life much easier. This pistol is also the one on the wall in the arena so you can get ammo for it.

If you get any challenges that require you to leave the Arena before getting the PaP pistol just quit and reload.

Once you have the PaP gun, the aim is to train around the arena an kill when you can. The main issue you will have will be the special zombies that spawn, the pistol can make easy work of them but the specials do have high range. Also the tigers can one hit kill so focus on them.

Don't worry about going down as you get 3 self revives. Obviously try to stay alive as long as possible as the will be more useful in the last few rounds.

Keep hold of your special (LB+RB)until it's needed as it can take some time to recharge it.

Just do basic zombie training and be smart about it and this will be no issue at all.

I advise starting off by slicing down a challenge banner right away and start working on your challenges.

As long as you don't get the "Slide Under A Blade Trap" challenge you will be able to complete the first 3 while staying inside the challenge area.

When you do that you will recieve a PaP pistol "Z-HARMONY" which I used all the way to round 20. It's very powerful compared to any other option and you can buy ammo off the wall of the challenge podium to stay stocked up throughout.

All of my Call Of Duty: Black Ops 4 HD Achievement Guides can be found here! :) (Mobile Friendly)
https://www.bradleafsfan9.com/call-of-duty-black-ops-4

I am posting this as a reference guide for anyone who may be having trouble or is just new to zombies in general. You just need to get to round 20 you do not have to beat round 20 and you cannot open anything. Doing this solo is easiest. Also, you can set the difficulty to casual.

Step 1 go over and knife one of the ropes holding the banners to activate the challenges which will end up getting you the Z-Harmony once you complete 3 challenges. If any of your 3 challenges require you to open anything up simply restart the game and try for different challenges. After each challenge go up to the podium and claim your reward to start the next challenge. I got knife zombies, headshot kills, and special weapon kills.

Step 2 always try to have 4500 points on you that way you can walk over and get ammo off the wall. Even though the Z-Harmony is a modified version you can still buy ammo for it from off the wall.

Step 3 train your zombies. For anyone new to this watch in my video how in the later rounds I take paths around the arena and get all the zombies lined up to follow. This will help with points when you shoot because bullets will penetrate as well as buy you time to kill them off.

Step 4 once tigers come always get rid of them as quick as possible. Shouldn’t be hard to do but you want to get rid of them quick because they can ruin your trains.

Step 5 when the armored guards come don’t stand in one spot too long, unload some bullets on them and then move so they can’t hit you or harm you. They will take more shots then regular zombies so just keep moving and be patient.

Step 6 when the daddy long leg creature comes make sure to shoot the humps on his back. He can shoot his tongue out so do not stand still at any point. Shoot while running always!

Helpful Tips

Nukes are your best friends

If you get trapped in a spot because of fire don’t panic, you should have enough room to train in that area as I show in the video at times.

Avoid the center podium at all times unless an emergency its not going to help your trains and will break them.

Never buy anything but ammo or guns from the wall, opening any of the gates will void the achievement.

Get a feel for the fire timing and patterns to help you with your trains and not getting stuck or hurt.

If you go down don’t panic you have 3 revives, so don’t stress I promise you can obtain this achievement just follow my steps and video and you will have it in about 30 to 35 minutes or less.

If you need any help, please message me I am glad to help!