Skill trees will be: Professional, trade, combat, criminal, wealth and influence. Characters of every social class will have access to all trees, but the cost will depend on the character's social class. In addition, there will be skill trees called "Industry" and "Inspiration" which will be available to Utilitarian and Romantic characters respectively.
The Victorian era was a collision of the utilitarian philosophy like that of John Stuart Mills and Jeremy Benthem, and the more Romantic and dualistic philosophies of Coleridge, and the conservatism of Burke. Conservative at that time not meaning what it does now. Characters should make a choice between the mysterious old world, and the mechanical brave new world. Therefore, at character generation, everyone will choose whether they are Utilitarian or Romantic.
For non-combat task resolutions, the two philosophies will have a different mechanic. Utilitarian followers believe in the supremacy of reason, of the miracle of consistency, and of the triumph of system over individual excess. Therefore Utilitarian task resolution involved adding up the relevant trait, the relevant skill, and checking to be sure that necessary components are present - and no element of chance. For example - Professor MacGillicuddy wants to build one of his meta-steam powered aerio-perambulators. He has the "head" trait of five, the "engineering" skill at three, and the requisite materials; a workshop, brass, wood, leather, canvas, and a Conyers-process meta-steam catalyzing engine. His total of "8" is sufficient to build the device which has a difficulty of 7, and he is a Utilitarian. He succeeds. His extra point can be used for performance, speed-of-assembly, or fanciness.
Across town, his arch-nemesis, the Romantic tinkerer Doktor Totenkopf is building a meta-steam powered Mechanical Turk Automaton. His "head" trait is four, his engineering is only a two, and he has the requisite materials; steel, brass, a Conyers-process meta-steam catalyzing engine, and a Babbage Difference Engine. Doktor Totenkopf's total is 6, and the difficulty of the Automaton is 7. Were he one of these pathetic Utilitarians with such limited vision, he couldn't construct the Turk. But! Doktor Totenkopf may be considered mad at the Academy, but his personal insight is unlimited. He draws a card. It comes up diamonds, which is a "+" suit for him. This increases his total to 7, and he succeeds.
I need to balance this, however - should Romantics have higher difficulties, representing the challenge of overcoming their own angst? How much? (That will depend on the random mechanic - is it a straight plus, minus, or no-effect...or is it a variable integer?
Next - Social Class is incredibly important in Victorian Society. Each character will be a member of one of three classes - Upper, Middle and lower.
Upper Class Characters: Have easy access to wealth, education, and influence. They must, however, abide by the rules of gentle society, which require that no gentleperson initiate an attack against anyone else. They may, of course, defend themselves if attacked, and likewise, may settle differences in a formal duel. If they break t his rule, they will surrender their place in society - losing all access to "upper class" skills, all their influence in society, and generally being considered dishonored. The majority of that penalty is roleplaying, but it should be important enough to warrant scrupulous attention paid to it.
Middle Class Characters - Have easy access to professional skills and education. They have difficult access to wealth, criminal, combat and trade skills, and very difficult access to influence. Middle Class characters must choose their social path - to be nabobs, and try and climb the social ladder (thus abiding by the rules of gentle society, even though they may never be accepted) or wallowing with the lower and criminal classes. If the latter, they may initiate and engage in combat without shaming themselves, but may never gain influences.
Lower Class Characters - Have easy access to trade, criminal and combat skills, have difficult access to education and professional skills, and very difficult access to influence and wealth. Lower class characters can do anything they can get away with - though society is carefully constructed to prevent that from being a detriment to anyone other than other lower-classmen. They may prey upon each other with relative impunity, but if they dare to assault or rob an aristocrat, and they will find the law out to get them.
The idea here is to have a mechanical effect that gives advantages and disadvantages based on each class, with each being distinctly playable. What's more, if someone wants to play the political game, and check out of the combat game entirely, they may do so and remain viable as a character.
Any suggestions, folks?