My android apps sometimes crash Say I am playing clash of clans or boom beach. A crash in the middle of an attack could be very fatal.

What happen is I was playing and then suddenly the screen go back to the home screen. No other apps are running. I can click the multi task button (or whatever button in bottom right) and the original apps shows up. However, it seems to be a crash because if I select it it reloads.

Does android have event logs I can check. What's going on? I got 4 GB memory. It's asus zenphone 2
Use logcat, the goto Android crash report tool. There are a few ways to use this utility: over adb, in an Android terminal shell, or with an app. If you have root, I suggest using an app like Logcat Extreme. 

Basically just start up the app, go to settings >> Priority Level, and check "Errors." Go back to the main screen, hit the record button. Now repeat everything you explained in your post, opening apps and checking recents. When you're done, go back to Logcat Extreme and hit the record button again. The log will be saved in the folder /sdcard/LogcatX.

The best method, which doesn't require root, is to use logcat in the terminal or over adb. There are a lot of guides for this. This one can help you logcat on Windows or Linux.