Oct 18

Trial and Error; Old and the New.

I remember reading Edge way back in the mists and a piece on trial and error gameplay . The designer’s (I forget who) example was Doom. As it was such a good example let me recite (from dusty memory):


  • You enter a room. Coiled around and through are a line of explosive barrels. Imps storm forth. You fire a rocket. Boom! Everyone dies – including you.
  • You play it again. Chaingun winds up and you take out imp after imp, but oh noes! A stray bullet and BOOM-BOOM-BOOM, the chain reaction of inevitable death.
  • Try it again. Shotgun. Up close. The imps go down as you work your way through the room, but a fireball that missed you hits a barrel…
  • Aaaaand again. This time you keep the barrels in front of you so no missed shots from them will ignite the chain. Then you work your way through till you get to a safe spot and then you shoot the barrels on purpose and clear out the rest of the room.


4 tries. You tried, failed and eventually figured it out. But was it fun? Was it frustrating? It’s a fine line. Here’s why…


Failure is more important to design right than success. Trial and Error gameplay in these modern times is much over looked simply because at its first implementation it can be incredibly frustrating. Regenerative health or shields (or both!) being the more accepted punishment for failing as they set you back some, but not completely.


I was very fortunate to be on the team that developed the recent NASA Kinect app Mars Landing.

It was created with the mindset of being a reflective experience as well as a game. Yes- the elements for mastering skills and scoring were added, but it was very important that the difficulty and complexity of the real event was conveyed – It’s not called the ‘7 minutes of terror’ for nothing! As you probably know, a lot of innovative and complex systems had to work autonomously, millions of miles away in conditions we only mostly knew about. Thus, the representative interactive experience had to be challenging but not frustrating.


Go download it now and play (link below – it’s free!). You’ll see that we integrated not only a fail-state for each of the 3 phases, but also an indicator that you’re getting close to it: On screen static gets worse the poorer your performance yet clears up as you improve.


Then came the balancing. As an experienced geared towards everybody 8 thru 80, and with part of the message being how hard this landing actually is; We wanted the average player to either fail or get through by a small margin the first time and then replay. The scoring system is then used as a metric of both ‘how close to failure’ and ‘how close to perfect’.


The tuning of body motion to actions executed was focused on this premise. Everyone should be able to mostly ‘get it’ on first play and then do well second play out. Which I’m glad to say we achieved with great success! Further replay and improvement will increase your score, possibly give you achievements and also change the ending.


To cushion the blow of failure, there is a rewind aspect to each phase: Fail, and rather than Game Over you are rewound back to the beginning of that phase rather than the beginning of the whole experience. Without this cushion the rage-quit rate would be much higher. The hit for failing needs to be tempered to your audience. Had this experience been geared for arcade play then we would want more of the classic Game Over.


In conclusion, trial and error gameplay has its place in today’s gaming medium but it must be used with great care, with a goal of providing challenge without frustration or boredom to its core audience. General rules of thumb:

  • Provide the player a challenge that is possible, but not effortless to achieve the first time out.
  • Ensure any failure feels justified as the player’s skill level and not unfair challenge or game glitch.
  • Penalize the player appropriate to the audience, the situation and the challenge.
  • Balance each success/failure as the game progresses to avoid sudden spikes.
  • Where possible, retain the same criteria for a challenge but alter elements so replay is fresh

Always remember, players want to be entertained and challenged appropriately to what they believe is fair. There will always be those that find something too hard and others too easy, so look to the larger middle group for your balance.



Images taken from the NASA Mars Lander Kinect App developed at SGI for and with Microsoft and NASA. Design decisions and tuning was not all done by me, all parties involved contributed.

Seriously, go download it!!!