Playtest is the process of testing an unreleased game for bugs, and feedback. As you develop a game you are constantly testing, tweaking and debugging it, but it’s important to involve other people, and not just at the very end.
Playtesting is a methodology but also an attitude towards the creative process, an approach that emphasizes problem-solving through iteration and collaboration with members of your audience. It can apply to many works that involve some interaction.
How to playtest
Playtest before you think you are ready as early as you possibly can. A playtest is not a presentation, if the WIP is too polished it may be too late. If you feel ready and comfortable to present and playtest your design, you have waited too long.
Simplify your project so that you can playtest today. Focus on what is needed to enable the next round of feedback.
Know why you are playtesting. Generating research questions in advance will also help you structure the playtest itself. What is the one key question that you want your playtest to answer?
Prepare variations. Go into a playtest with different versions of your project to try out. This allows you to make the most out of the playtest session and it also helps you to try out new ideas during the playtest.
Blame yourself, not your playtesters. Remember to warn your playtesters that they will be interacting with an unfinished, rough version of what will at some later point be a smoother experience. Be sure to tell them that if they are frustrated or confused, it is not their fault. The most valuable part of the playtest is not what they do understand, but what they donʼt. Be grateful to your playtesters.
Know your testers. If you are meeting them for the first time or donʼt know them very well, talk with each person and take notes that will help put their reaction to your project in context (non-gamers, hardcore games, other designers).
Don’t explain. Resist the temptation to explain the ideas and intentions behind your project to your playtesters. By explaining your ideas beforehand, you are ruining the chance to see the authentic reactions that your project provokes.
Be selfish. The purpose of your playtest is not for your playtesters to have fun. Don’t worry about being entertaining.
Answer a question with a question. Donʼt tell them what the blue button does. Instead, ask them what they think it does, or even better, what they think it SHOULD do.
– Creators say as little as possible during playtest (except controls and brief instructions that would be communicated by the game) and just take notes while the other play.
– Playtesters try a few sessions playing normally, and then a session playing with the intent of trying to break the game (Quality Control).
– Ask playtesters to think out loud. Tell them to explain what they are thinking and what motivates their choices. Discourage them to do a critique while they play.
– Brainstorm after you are done, you can have a proper conversation with comments and feedback and unexpected suggestions afterwards.
Summarized from a Playtesting Primer