Z-Axis in Diner Dash

Why do people burn popcorn?

a) They like the way it tastes.
b) They can't follow directions.
c) They don't pay attention.
d) They want to test their smoke alarms.

Though compelling, none of the these answers get at the true reason. People burn popcorn because they are greedy. Making popcorn involves a simple risk reward scenario. If I let it heat longer, I get more popcorn. If it over heats, it burns and I lose popcorn. If I am watching the microwave I can clearly see that the popcorn bag is full. I can stop it anytime to eat what I see. But I wait in hopes of getting more. It's the old "bird in a hand" proverb.

A good game gets players to make these tradeoffs and understand the rewards. The term to describe risk/reward decisions that add a third dimension to gameplay is called z-axis. Z-axis was coined by designers at Playfirst. My objective as a designer is to get the player to make meangingful decisions. The more satisfying those decisions are, the more succesful the game. Diner Dash is the top new casual game franchise. Let's take a look at how it works.

Here are five examples of Z-axis in Diner Dash:


1. Colormatching

Risk: Seat guests by color. Risk losing hearts.
Reward: If you match color, you gain multiplier bonus points.

2. Crab Sticks, Bread, or Pappudum

Risk: These bonus items in restaurant 3 and 4 could delay you from helping other customers, risking heart points or interuppting a chain.
Reward:Gain bonus points.

3. Chaining

Risk: Keep guests waiting you could lose hearts.
Reward: If you wait until everyone is ready at the same time you can collect chaining bonuses for doing the same activity in a row.

4.Tipping
Risk: Risk a good tip from a moderate tipper in exchange for a tip from a high tipper.
Reward:Gain higher tips.

5. Long line

Risk: Keep guests waiting too long you could lose hearts.
Reward:Queue up people until everyone has arrived and then seat them according to impatience and color.

Giving the player clear feedback makes these decisions rewarding and ultimately interesting. Designers can layer z-axis decisions on top of each other to add even more variety to the gameplay. Furthermore, features like the podium and special drinks extend the risk/reward ratio making different strategic choices possible. Then you can even layer on interesting obstacles like in level 18 where you serve all business women or long tables.

Where to go from here:
One option not explored in these games is time pressure in the level. I never get the feeling that if I take too long to serve everyone that the chef will bail and go home. It makes the queueing strategy too easy. The only thing that breaks up the repetitiveness of that strategy is the fact that the first level in each has no podium. The "no podium" levels are more challenging because you have to observe more. Additionally, the game would be more challenging by increasing the score goal. I usually clear the expert score by a couple thousand. A higher point goal would cause me to make more z-axis decisions.

Next steps: An interesting follow on to this blog would be a discussion on how each of the upgrades affect the z-axis and a deep dive in the types of strategies you can employ. I would like to wrap-up the report with some video and send it developers with a bag of popcorn. I want to inspire game designs that pop.