Sometimes, the developer of a videogame decides that the player(s) should be bested by their opponent(s) for the purposes of the story, regardless of the player's skill, luck, or accumulated experience points and equipment. It is in this situation that the player shall plunge headfirst into one of the single most infuriating elements of the JRPG, the Unwinnable Battle. I say “of the JRPG” because, let's be honest, Japanese console role-playing games are by far the greatest offenders in this catagory. You'll run into Sephiroth Clone #42 at the end of a big, long dungeon about twelve hours into the game, and he'll laugh and tell you about how you have absolutely no chance of beating him. The defiant spiky-haired protagonist will issue a remark regarding his desire to refute these claims, and the battle begins.
Here's where the fun part begins. Many Unwinnable Battles are not clearly such when they first begin, and occasionally, a Very Definitely Winnable Battle will appear to be an Unwinnable one. The player will have to rapidly determine if this is a fight they are supposed to win or lose, and adopt the appropriate strategy. Depending on the nature of the unwinnable battle, it may be:
Occasionally, an Unwinnable Battle will, in fact, be Winnable, but with the exact same game progression consequences (see Valkyrie Profile). In some cases, winning this battle is actually punished; in Tales of Destiny, if the party defeats Leon when he attempts to capture them a few hours after the beginning, the game will end right there because you're supposed to get captured by him in order to get dragged into the main plotline of the game. Experts agree these sorts of game-ending results are pretty fucking lame.
This technique is typically a hallmark of a hack game designer.