As we examine Loki's career in deceit, we quickly find that ...
Loki Has The Ability To Trick Exactly One Person
In the first Thor movie, Loki is supposedly on good terms with his more muscular hammer enthusiast brother, who is in line to take over the throne of Asgard from Odin. No one suspects that Loki -- the pale, brooding, jealous schemer with the greasy black hair -- is secretly up to no good.
Loki hatches a fairly simple plan: Stage an attack by the hated frost giants which will create a rift between the bloodthirsty Thor and his peace-loving father. Loki secretly lets the bad guys into the palace, and Thor, falling for it, is enraged and launches an unauthorized retaliation on the frost giants' planet. Odin puts a stop to it and banishes Thor to earth, leaving Loki a clear path to the throne. The trickster god has fooled everyone!
Oh wait, no, everyone sees through it immediately. Seriously, the very next time we cut back to Asgard, four of Thor's friends are sitting around a fireplace, and one of them says, "You know, this all worked out really well for Loki, and also his only personality trait is that he lies all the time. I bet he let those shitheads into the palace." That's it! It didn't take any masterful detective work or any real discussion.
The four confront Loki, who says Odin is in a coma (which is true) and then tells a series of lies -- that the queen is unavailable to speak to them, and that he is forced to leave Thor on Earth due to imminent war. The four friends do not believe this for one second, the trickster god again utterly failing to trick them in any way.
*whispers* "Is he actually crossing his fingers in front of us while he's talking?"