Video game concept development drafts the blueprint design of the game. The flow of gameplay is best drafted here and best refined when the overall project is in a workable state. During this process we can determine what the player sees and what happens at each state of the game.
It's very common to see flowcharts during the concept development phase of a video game. Programming isn't a difficult skill to develop but using those skills requires direction. Flowcharts provide the direction to programmers needed to take a project from concept to playable. You can think of flowchart as a planned pathway for the player to follow that's loaded with events and points where conditions are checked determine what happens next. The pathway will start the player at the begin block then run the player through loops and if statements until the reach the end block.