Tales of the Abyss: Cute Bruiser Anise is secretly being forced by the game's Big Bad to act as his spy inside the party. His leverage over her is her parents, who are being held hostage in the city of Daat under the pretense of being housed inside the religious citadel there. At one point in the game, the party, including Anise, goes to Daat to break out one of their friends, who is being held under heavy guard in a military garrison adjacent to the citadel. This poses no great challenge. You'd expect: Her to realize that her allies are more than strong enough to rescue her parents, tell them what's going on, and beg them to stop off and collect two more passengers. Instead: She says nothing, and isn't revealed as a traitor until she openly turns on the party and helps the villains to murder the person who is essentially the Pope of the religion that she personally follows - and who, for extra irony, is the person they went to Daat to save the first time they were there. Bonus Idiocy: She is, of course, Easily Forgiven. With a side helping of being forgiven for her hypocritical tongue lashing of the main character earlier and her horrible treatment of her Rival who just called her out for it all. Extra Bonus Idiocy: There are 3 major powers in the world. She spends the game traveling with the two heirs to one of the powers, the second-in-command of the second power, and the leader of the third power, all of whom dislike the big bad she is controlled by, along with having one of the worlds only flying machines... guess when she takes the opportunity to inform them of what is happening and ask for help.
Everyone is investigating the cause of recent fires in Izoold. It's been proven that the fires have been caused by a light-frog. A bit of investigating shows that a common factor linking every fire was that seafood gels were involved. However, light-frogs don't normally feed on seafood gels. You'd Expect: Everyone figures that if seafood gels are common in each fire, they must be involved somehow, right? Instead: Everyone adamantly refuses to acknowledge that this is even possible, despite the fact that the very presence of a light-frog in Izoold is unnatural. Absolutely every time you bring it up, they consistenly tell you how impossible this is, and even when you finally kill the damn thing by baiting it with seafood gels, everyone is absolutely shocked that the only common factor in the fires could've been the cause. Additionally: Nazdrovie!
In the same game, Ratatosk Emil had used his Ein Soph Aur on Richter, which Ricter reversed with Eternal Recurrance right back at his face. A few cutscenes later, Ratatosk Emil runs into Richter again. You'd expect: Emil to remember what happened the last time he tried to use Ein Soph Aur and not use it this time. Instead: He uses it again, the predictable happens and it gets reversed right back at him. To top it all off, Ratatosk Emil still has that same shocked look on his face that he did when it was reversed the first time.
Towards the halfway point, Judith discovers that the party's ship's Blastia core is actually a Hermes Blastia and, naturally, destroys it. The rest of the party, who are unaware of the history of Hermes Blastia, demand an explanation. You'd Expect: That Judith, who clearly considered the party her friends, would explain how the Hermes Blastia are extremely harmful to the world, and must be destroyed. Instead: She refuses to explain anything and outright abandons the party, effectively betraying them. Not only does this cause considerable tension and angst within the party, it also directly leads to the party coming into conflict with the Hunting Blades guild. Bonus Idiocy: Judith could've at least waited until the boat docked and they all got off the ship first, or is the word "patience" not in her vocabulary?
During the party's trip through the desert, the characters suffer from heat and dehydration. You'd Expect: Rita, a mage who can create large quantities of water with magic and regularly does so while fighting enemies, to use this spell to provide refreshments for the party. Instead: The party is stuck popping cacti for water until they eventually collapse from heat stroke after the Boss Battle.
During Hilda's character segment in Tales of Rebirth, they encounter Naira, who happens to be Hilda's birth mother. However, Naira is aware of a dangerous prophecy and fears it may harm her daughter. You'd Expect: Naira to calmly tell her daughter about the prophecy and how she fears it will kill her, and try to encourage her to leave town for her safety. Instead: She rejects Hilda, rips up Hilda's treasured Tarot Cards, refuses to talk to her, only revealing things when Tohma shows up, and she performs a Heroic Sacrifice to protect her daughter, which could've been avoided if she had just opened up. Sheesh!
During the beginning scenes of Tales of the Tempest villains Lukius and Rommy storm the church in the village and sets fire to the priest inside, killing him. Said Priest's wife approaches from the outside where the hero Caius was watching this all go down. He then stops and warns her that her husband's killers are still inside and that it's dangerous. You'd Expect: That as someone with absolutely no combat ability she would heed Caius' warning and wait until the killers left before getting near her already dead husband, after all, she still has a child to consider. Instead: She walks straight inside, goes right up to where her husband died (and his killer is still standing), and without even putting up a token resistance, gets set on fire and dies as well.