Why does Ariadne's totem work?

Question

In Inception, Cobb's totem was a spinning top, that in reality would stop spinning eventually.

Arthur's totem was a special dice, that in reality would roll a particular number more often.

Ariadne's totem seems too simplistic for that purpose... a chess piece (bishop) that she knocks over.

I realize she drills a little into it, possibly making it lighter or changing the center of gravity to make it easier to knock over... but that seems too simplistic... a projection or another person in her dream could easily replace that totem that she would knock over, and it still goes over...

It seems to me that in order to work properly as a totem, it would change state in only a way you would know to expect as validation of YOUR dream or someone else's dream. Whereas Cobb's totem's action is only known to him/Mal and Arthur's totem's special feature is only known to Arthur as well, Ariadne's totem seem too easy to copy by another architect. Why does it work as a proper totem?

Answer 1

It follows the same concept as Arthur's special dice, basically the exact same concept.

Consider for example, how Arthur would know the die is his. He couldn't just rely on which face the die landed on. For one thing, a loaded die doesn't always land on the same side. And then if it did, and that was his check for the totem, it would just take observation to be able to fake his totem and trick him in a dream. What Arthur would know and be checking for when he picks up his die is the weight distribution. He had to become intimately familiar with the weight and feel of his particular die, and this allows him to know that it is his.

Ariadne essentially did the same thing. She machined her bishop to have a specific weight distribution that isn't apparent just from observation. She knows what the weight distribution of the bishop would feel like (and can test it by knocking the bishop down, similar to how Arthur would know the feeling of throwing his loaded die).

It's not about how easy it is to knock over, it's a combination of how easy it knocks over, how it feels when knocking it over, which direction it goes, etc. Someone just observing the bishop fall might be able to come close to reproducing the weight distribution; but because they don't know how much force she applies when handling the piece, they can never perfectly replicate it if they don't pick it up themselves. This is why the rule was to never let anyone else touch your totem. They need to be sure they are the only ones who know the specifics of the totem.

Even Mal's top would have had it's own weight distribution presumably. A top spinning on it's own isn't a very secure totem and could easily be reproduced by someone else's dream. They wouldn't know the weight distribution though, and that combined with never letting anyone else touch it is one of the few ways you could ensure someone doesn't dream a copy of it through observation.

Answer 2

According to the screenplay, Ariadne's totem has a specific tipping point. When it's tilted to a certain angle it will topple over, and because she drilled out a small portion of the metal under the felt, the weight distribution is not immediately visible to the naked eye.

Close on a small BRASS CHESS PIECE. Ariadne tips it over. Frowning, she picks up a micro drill, peels back the felt on the bottom and widens a hole in one side of its base. Tests the TIPPING POINT again. A NOISE makes her look up.

_{^{Inception: Screenplay}}

When she uses it, she's not specifically looking to see whether it falls over or how it feels in her hand, but rather the angle at which it starts to fall. Too soon or too late and she'll know that she's in a dream.