The loop is one of the fundamental concepts of game design. Identifying the loops in your game helps keep the design work more in focus, precisely identifying what makes the product compelling (and freeing up the developer’s efforts to make those features even more robust.
The simplest loop of all is a cycle composed of two repeating steps:
1) Action: the player performs an action (for example, presses a button on the controller).
2) Reaction: the player receives feedback regarding the action just performed (for example the controlled character makes a jump).
In video games, however, the user is usually motivated by the desire to progress towards his goal, so we need to add something to our definition of loop:
1) Motivation: the player wants to achieve a certain goal.
2) Call to action: The game provides a way to progress towards the goal.
3) Action: the player performs an action.
4) Reaction: the player receives feedback on the action performed and the progress towards the given objective.
Most games have multiple loops, working on different levels and time scales, both short-term and long-term. Loops can be nested, with larger loops composed of smaller ones. Each of them can lead to another loop with the player’s goals redefined each time a loop is completed.
Some examples of loops that can motivate players are as follows
1) Line up matching gems on a board to earn points (objective: get enough points to pass the level).
2) Kill monsters to earn in-game currency (goal: make enough money to buy an item).
3) Collect in-game currency and buy items with it (goal: reach the maximum power level of your character).
4) Complete the quest (goal: reach the next chapter of the story or get a good reward).
5) Run, jump and die (objective: improve your skills to do better in the next race).