How do you roleplay characters with superhuman intelligence?

[Keltest]

Regarding playing superintelligent NPCs, the trick I tend to use as a GM is to cheat a little.

For practical purposes, I think this is probably the solution. As a DM or player, you have to metagame a bit. Maybe the DM lets you have restricted access to the notes to represent your better memory. Maybe a successful roll to know something yields more data. Maybe youre allowed a little bit of retroactive preparedness.