Rollerblade Office Chair Wheel Chock

I wanted to keep my chair from rolling when playing racing games but all the chocks I found required the chair be lifted up and set on the chock and you needed all five wheels in them or the chair was unstable. 

For these you only need 2 because the chair still sits on its wheels.

Put the chair where you want it.
Unweight the chair (get your butt out of it) and slide them in.
When you are done, slide them out.

If you really want lock in, try cat tongue rubber tape https://cattonguegrips.com/products/non-abrasive-grip-tape and trim the inside. 

NOTE: These work best if the larger side of the wheel faces the back of the chair and you keep the grippy tape clean.