Among the great advantages of game-based learning is, in well-designed games, that players are “tested” exclusively on skills, knowledge, understanding, or attitude that they have learned, or should have learned, while playing the game. Certainly, there are exceptions. Games can be badly designed. Or, problems of familiarity might arise, as discussed in Ludotronics, when conventions of a certain class of games (misleadingly called “genre”) raise the Skill Threshold for players who are not familiar with them and might also interfere later in test situations. Most of the time, though, players are indeed tested on what the game has taught them, and well-designed “term finals” like level bosses do not simply test the player’s proficiency, but push them even further.
This rhymes beautifully with the rule “you should not grade what you don’t teach” and its extension “if you do teach it, grade it only after you taught it.” While this sounds like a no-brainer, there are areas in general education that have a strong tendency toward breaking this rule, with grammar as a well-known example. And then there’s the problem of bad or insufficient teaching. When students, through no fault of their own, failed to acquire a critical skill or piece of knowledge demanded by the advanced task at hand, how would you grade them? Is it okay, metaphorically speaking, to send students on bicycles to a car race and then punish them for poor lap time performances? But if you don’t grade them on the basis of what they should have learned, doesn’t that mean lowering the standards? As for the students, they can’t just up and leave badly designed education like they can stop playing a badly designed game.
Another aspect, already mentioned, is that tests in games not only test what has been taught, but are designed to push player proficiency even further. This is possible, and possible only, because the player is allowed to fail, and generally also allowed to fail as often as necessary. Such tests, moreover, can become very sophisticated, very well-designed. In Sekiro: Shadows Die Twice, you might be able to take down a boss with what you’ve already learned instead of what you’re supposed to be learning while fighting that boss, but you’ll be punished for it later when you desperately need the skill you had been invited to learn. You can read all about this example in Patrick Klepek’s “15 Hours In, Sekiro Gave Me a Midterm Exam That Exposed My Whole Ass,” which is recommended reading.