Scientist villain builds (non-magic)

[CaDzilla]

I want to make some villains who mostly use scientific ways to fight. What feats, skills, equipment, and classes would suit them best? They also can't use magic/psionics or be of an NPC class

[Fosco the Swift]

The best way in D&D to get a mad scientist feel to a villain is actually to use a new class altogether. D&D is not made for actual science, magic and/or alchemy rules over it. Because alchemy is a mix of magic and science, its the best compromise you can find. Look up the Pathfinder Alchemist from the Pathfinder: Advanced Player's Guide for this perfect mix.
The Alchemist is technically a spellcasting class, but "casts" spells by drinking Extracts that he makes at the beginning of the day. They also have Mutagens: alchemical elixirs that boost a physical ability score at the penalty of a specific mental score. They additionally create bombs that are treated as splash weapons dealing damage that increases like a rogue's sneak attack ability. Discoveries are learned every even level that allow for bombs to deal different elemental damages (such as cold or sonic instead of fire) and other varying abilities. Check Pathfinder: Ultimate Magic for more Discoveries.
Hope this helped.

[(Un)Inspired]

The pathfinder class the alchemist is sorta like a medieval pseudo-science version of a scientist. Also check out the pathfinder technology guide for lasers and stun rods and junk.


Edit: ninja'd on the alchemist

[atemu1234]

There are classes in Ravenloft that could do this- I can't remember which, but if you can get your hands on Legacy of Blood, one of the houses gives information on science-y characters you can make. Look into it if you get the chance.

[QuickLyRaiNbow]

Look into Arsenic and Lace: The Poisoner's Handbook; I'm pretty sure that's what it's called. It's basically the definitive guide to optimizing poisons.

[Qwertystop]

Someone on the Homebrew forums made an entire subsystem for magic-science. Called it Gramarie. It's spread quite a lot since then. It's kind of complicated, but it's basically a freeform artificer with more time requirements - they don't make items that cast spells, they make the parts and put them together. For example, they could make an engine out of silver that uses sunlight as fuel to move up (no other directions - horizontal is made of iron and fueled by wood, down is made of flesh and fueled by blood) and pin that to a wall that only stops living things, and use it as a mobile bombing platform. And that's on the really-really-simple end of things - at minimum, you could do quite a lot figuring out what to use for bombs.

It's got a subforum on minmaxboards (http://www.minmaxboards.com/index.php?board=152.0), a discussion thread here, (http://www.giantitp.com/forums/showthread.php?320298-My-Little-Gramarist-SCIENCE!-is-Magic-Gramarie-Discussion) and even a TVTropes page that I'm not linking because it's TVTropes.