This issue is a particular fly in my ointment. When certain concepts are established in a story, it is unwise, not to mention half-assed, to contradict it later on. Many will argue this point, saying that the story is fantasy/ fiction and shouldn’t be taken seriously. Regardless, a story must keep the original foundation it was built on, or else it will collapse and lose its integrity.
Think of it like this. You’ve created a new game. Now, that alone should tell anyone not to take it seriously, but there are SET RULES that come with the game: the levels, the point system, the tools, the characters, etc. Every player MUST follow these rules once it’s been established. If a player reaches the middle of the game and a different set of rules appear out of nowhere, then the game is a FAIL. If certain players gain privileges that they didn’t earn, then the game is a FAIL.
Again, this is where that trusty beta comes in. During the initial read, they should be able to point out the inconsistencies within the plot and with the characters actions. The rhetorical battle-axes that say, “Hold up! You said in the first chapter that these creatures can’t get wet or eat after midnight. Then why is Gizmo taking a shower and eating a ham sandwich at 2 AM, with no consequence? I call bullshit!”
No matter what genre of fiction an author writes, they have to follow the rules they set for their world. They can’t just turn mid stream and make up a lame excuse as to why. Just like game design, every story requires a plan and legitimate solution for every conflict, every situation. If not, somewhere down the line, the author will write themselves into a corner, and the story becomes … say it with me folks … A FAIL!