As a player, would you prefer to be told “to revert your previous move, click on the UNDO button located on the bottom left corner“, or for such a button to be clearly shown to you, and when clicking it (after being subtly induced to do that), seeing the result? From my experience, most players don’t like reading and will ignore a text even as short as that. And when playing, they expect an active experience (interacting) rather than a passive one (reading). The trick is to induce them to do something without telling them explicitly . But sometimes some things are difficult or time consuming to show, and the most efficient way to explain them is to clearly state them. As an example, when you want to rotate more than one piece in Flip, you grab the innermost and move it outwards. There are several reasons (outside of the scope of this post) why you cannot pick the outermost and move it inwards. Unfortunately, I have still not found a better way to transmit that idea than to state it explicitly: “rotate from inside to outside”.