We were trying to understand how the “Action Surge” rule works, and after some discussion we came to a standstill.
Starting at 2nd level, you can push yourself beyond your normal limits for a moment. On your turn, you can take one additional action on top of your regular action and a possible bonus action
The keyword “possible” is what threw us off. Half the group thought it meant “additional action or bonus action”, and the other half thought it was “additional action and bonus action”.
So which is it?
No it doesn’t give you another bonus action. The optional part is that if you haven’t used your bonus action that turn you can still use it after the Action Surge (AS).
So it could be:
Action → Bonus Action → AS Action
Action → AS Action → Bonus Action
Source
To quote the rules:
You can take only one bonus action on your turn, so you must choose which bonus action to use when you have more than one available.