En passant

Is the En passant move in effect in all games and by all rules? (I do not remember My rule book in high school educating I on this matter.)  I knew it taught first move of pawn could go one forward, two forward, or if a opposing player's piece could be captured by one forward and one diagonal of the moving piece the moving piece could capture it.  So it seems this En passant utilizes the eligible two forward ability on first move of pawn, but the opposing player's piece is the capturing retro on the next move in passing.  Any one care to offer explaination as to this?  Thanks in advance for any response. 

Yes, en passant captures are always allowed when they are supposed to be.

If you could provide a link to a game where you think it didn't work properly, please post it.

Ah excuse Me notmtwain, I was not referring to Chess.com chess gaming only a specific: I am thinking I had a rule book and it did not include or made optional En passant?

Also are you at all familiar with the one forward and one diagnol if for capture that I above describe?

notmtwain.  How outlandish or allowable for the fun of it only would it be to play a game where each player makes two moves (that being with two separate or maybe the same piece?) and then it is the is allowed His or Her turn of two moves? Do you know any variations of or on the ordinary game: I think some might be source-able on here but I have yet to browse so deep.

So a clarification of My original question might be: is En Passant a as of to the rules move of most chess game chess rules?

Yes, it is true, En Passant is to as the rules as taught in your High School very much a legal move. Furthermore, as to and such as therefore to the rules pertaining En Passant, moving one two squares as opposed to one is sometimes advantageous regarding moves such as d3, d4, etc.

Understanding En passant is the mark of Chess mastery. Read this very informative blog post for more information: https://www.chess.com/blog/VladimirHerceg91/using-en-passant-to-gain-a-mental-advantage

http://rules.fide.com/images/stories/Laws_of_Chess_2017_-_PB_approved_v4.pdf

Section 3.7.4.1