A Firefox game opens but its rules window does not: check for a blocked popup
If a game keeps running but clicking its Rules button produces no new window, check whether Firefox indicated a blocked popup. Record the game address and the exact control you clicked.
Read the setting
Firefox Page Info shows site-specific popup permissions. Compare that setting with a visible blocked-popup indicator. A game can also show rules inside the existing page, so a missing second window alone does not establish the cause.
Compare a specific example
For example, the table responds normally but a rules link triggers Firefox’s blocked-popup notice. Look for a rules page on the publisher’s own site and keep global blocking in place. If there was no Firefox notice, check whether a panel opened behind the table or whether the publisher offers a separate rules link.
Frequently asked question
Does this explain a blank game screen?
This comparison covers a secondary window. A blank main game needs a separate check.