GURPSよろず

　You can brew one specific elixir without knowing Alchemy.
This calls for the usual time, equipment, and ingredients, and obeys the standard rules; only the skill roll differs.
No matter how many Rote Alchemy perks you have, you cannot use any of Alchemy’s other applications or recipes.

　To concoct the elixir, roll against a spell capable of producing the same results, if you know one.
If a spell is very similar but not identical, the GM’s word is final.
Otherwise, roll against IQ.
Both alkahest (Magic, p. 220) and paut (Thaumatology, p. 52) are valid elixirs, and use IQ – not a spell – as effective skill.
The Elixir of Lichdom uses the Lich spell.
In allcases, the recipe’s Alchemy skill penalty modifies the score used.

　Example:
Amaranda-44 is a sorceress with IQ 14.
She wants to brew Elixirs of Luck, Magic Resistance, and Speed without studying Alchemy.
Luck calls for Alchemy-3; no spell produces its effects, so Rote Alchemy (Luck) lets Amaranda brew the elixir at IQ-3, or 11.
Magic Resistance is also at Alchemy-3; the Magic Resistance spell can emulate it but Amaranda doesn’t know that spell, so Rote Alchemy (Magic Resistance) gives her an 11 there, too.
Speed is at Alchemy-1; the Haste spell is identical and Amaranda has that spell at 18, so Rote Alchemy (Speed) gives her a 17!
Amaranda can’t brew elixirs other than those three, analyze elixirs (even those three!), or otherwise use the Alchemy skill.

　Rote Alchemy is typically acquired as part of a magical style that includes spells that have elixir equivalents.
At the GM’s option, it may exist for other spells – if he’s willing to set costs, durations, skill penalties, and so on for oddities such as the dreaded Elixir of Decapitation.