and similar back-story delivery tropes.
|In Planescape: Torment, you play as|
the aptly-named Nameless One...
While this approach certainly has a few advantages - it saves time during development, provides narrative cohesion and enhances immersion (if done properly) - it is often used as a crutch when character design is either lacking or non-existent; many offenders of this trope are bland, one-dimensional characters that use amnesia as an excuse to not have any personality of their own.
|...an amnesiac immortal with a|
penchant for dialogue.
Torment is structured around this concept, with most (if not all) of the game's mechanics being explained via amnesia; gaining levels is mostly remembering past knowledge, most of the party characters are linked to his past incarnations and a good part of the game's plot revolves around acquiring his previous memories. It's therefore apparent that amnesia can work as (and even enhance) the game's story and narrative if it's treated as an integral part of the experience, instead of a fall-back method to shave time off development.
What to Improve: The best remedy in this case (aside from going the Planescape: Torment route) would be to refrain from using amnesia altogether; after all, this is probably one of the most overused tropes in the narrative delivery department. Barring that, however, better integration into the story is probably the best way to go - as an example, gameplay tutorials can be incorporated as "flashbacks" into the protagonist's past - while making sure that said integration remains an interactive part of the player's experience (don't resort to non-interactive sequences such as cutscenes or take over the controls to illustrate such scenes).
Game Mechanics / Story Segregation
|In Final Fantasy VII, weapons like|
this are hard to get...
Such actions often shatter the in-game world's verisimilitude - the suspension of disbelief that helps immerse the player into the experience - effectively wreck any attempts at atmosphere the designer(s) may have tried to implement.
|...though, judging by cutscenes, the|
starting blade is Cloud's favourite.
What to Improve: Facilitate better communication between the story and game mechanics teams during development; often, the challenge of integrating (and explaining) various gameplay aspects into a coherent story line can be difficult, but offers great rewards by means of immersion and consistency. Alternatively, if you absolutely must break the game world's "rules", at least attempt to justify such actions; in the above example, the character could have been inflicted with a status effect that disables resurrection items from being used (which would also work as an actual in-game ability for better cohesion).