Tin foil hat
|[ tinfoil hat (UnNetHack)|
|Base price||1 zm|
The tin foil hat protects the wearer from damage from a (master) mind flayer's psychic blast, with the downside that it also prevents the wearer from sensing monsters by telepathy. This applies to any active source of telepathy the player has—including, in SporkHack, the helm itself, if it happens to be the random appearance of the helm of telepathy. This means that in any game in SporkHack, there is a possibility that you will not be able to count on a helm of telepathy being an effective source of ESP for your ascension kit.
In UnNetHack, the tin foil hat is weightless and made of metal (which does not rust or corrode), and, like the dented pot, does not require a full turn to wear if the player is fast. However, it does not contribute to the wearer's AC, giving it little value apart from its psychic protection. With a base price of only one zorkmid, surplus tin foil hats are probably not even worth saving for the next shop you encounter.
Tin foil hats are head coverings made from aluminum ("tin") foil, which (supposedly) protect against attempts (by government organizations, spies, extraterrestrials, etc.) to read or control the wearer's mind. The theory is that the foil functions as a Faraday cage, a device that prevents electromagnetic waves from entering a space, in this case the wearer's brain. In practice, however, foil wrapped around the head does not make an effective Faraday cage. (Real Faraday cages are made by sufficiently enclosing spaces with metal sheets or grids.)
Because of the questionable theories behind them, tin foil hats are stereotypically associated with conspiracy theories and paranoia, which gives the phrase "tin foil hat" a generally negative connotation. Some communities have "redeemed" the concept, though, with tongue-in-cheek tin foil hat design contests.