How do I Put a Game or Puzzle in a Forum Post?
Chess.com allows users to insert their own puzzles or games into forum posts and blog posts! This can be a fun way to give daily puzzles to your club, or to discuss a game. Here’s how:
In the option bar above the text box on a forum or blog post, click the game board icon:
This will take you to a game board where you can add your game or puzzle:
There are several options of what you can do, listed on the right.
Add a game
If you want to add a game or a series of moves, there are two ways you can do it.
1. Just make the moves. If you want, you can just grab the pieces and start making moves on the board, and the moves will be recorded:
When you are done, click ‘insert’ at the bottom right, and the sequence you played out will be added to your post for others to look at and interact with.
If you want to add details about the players and game, you can do so in the Details tab:
You can also add a full game without making all the moves on the board. You you can load a PGN or a URL of a game that was played online, or one you have already copied down, by using the options on the right side of the board. You can also add a FEN, which is a single position in a game. 
This will add the full game, as well as all the details into the details tab of who the players were.
See here how to get your PGN or FEN from your game. You can also simply load from the Chess.com URL of the game you want to add!
Add a puzzle
To create a puzzle with a solution that other members can solve by moving the pieces themselves, start by clicking ‘setup position.' This will open the following menu:
Add pieces by dragging them onto the board, or remove pieces by dragging them off the board on the right side. You can also clear the whole board by clicking the "trash" icon, then you’ll be able to add whichever pieces you need, wherever you need them by dragging them onto the board.
Play the moves! Once you’ve set the board up how you want it, click on ‘moves’ and play out the moves that will solve your puzzle.
One you reach your final position, the point where the puzzle will be solved, then go down to the Theme menu and check the Puzzle box:
This will set the diagram as a Puzzle, which means other members will be able to move the pieces and have Black respond accordingly.
If you do not click the Puzzle box you will only be inserting a diagram with all the moves visible for members to click through.
The Theme menu is also where you can set the type of pieces and color of board.
When you are all ready, click insert and the puzzle will be inserted into your post! Finish writing your post, submit it, and other people reading the forum will be able to interact with your game or puzzle:
There are other advanced settings you can also use, such as setting whether en passant is possible, or who has castling rights. You can read more about these advanced settings here.