Question: As much as the answer is known to be a "Yes", I want to understand the following:

1. Can I buy a preowned (used-very good/like new) game to use in PS4?
2. What should I not be expecting from a used/pre-owned PS4 game?

The question behind this is the Call of Duty: Advanced Warfare which I believe has gone down to an affordable range and I think I can buy one. But wasn't sure if I can actually play it normally?

Answer: 
As [DGarvanski has already covered](https://gaming.stackexchange.com/a/243637/73976), there isn't any weird checking if you want to use pre-owned games on PS4. Like most pre-owned games however, *if* there was any additional content that was unlocked by the use of downloadable content, or passes or something similar, the likelihood of this still being available for a pre-owned game is unlikely, as they are only one-time use.

For future reference, Playstation have released an official guide for sharing/using pre-owned games on the Playstation 4 system:
**Yes, you can play it normally.**
The PS4 allows the use of pre-owned games without any online checks or weird DRM. I've checked and Call of Duty: AW has no "Online Pass" system in place so you wouldn't have to buy anything extra in order to play. The only thing that will be different is if you buy a special edition since you wouldn't have access to the DLC that comes with that edition unless you buy it separately . However, the PS4 will not have any problems with you playing a used copy.