[Yevgeny Borisovitch Volgin]

I'm trying to think of an A/Rt build. Anyone got any ideas?

And I don't want one of Ratty's silly painting puns.

[Goto]

Well I have zero experience with Rits and their skills, but my suggestion would be to see if you can find some weapon spells that would work well on an Assassin. I guess that will depend a little bit on what campaigns you have. Brutal Weapon would probably be fairly effective, since you wouldn't have to invest much in order to get a indefinitely sustainable damage boost, useful given the lower regular damage of daggers. Keep in mind it prevents you from utilizing enchantments though, and be wary of whether party members are likely to be enchanting you.
Warmongers Weapon is another possibility, that would give you extremely potent interrupts against spellcasters. Nightmare Weapon is of limited duration, but might be useful as healing. If you've stuck some points into Channeling Magic, consider taking along Wielder's Strike to provide some reasonably powerful ranged damage. Ghostly Weapon or Sundering Weapon from EotN could also be useful, if you have it.

So yeah, there's some interesting stuff to take from Rits. Most of these work under the assumption that you'll be using daggers, so take an attack skill combo of your choosing I guess. You'll probably want reasonably high points in Dagger Mastery and Critical Strikes, perhaps Critical Eye to help with energy management. If you're not going with Brutal Weapon and are free to use enchants, I can't really recommend Critical Agility highly enough. Critical Defenses can also be a nice addition, providing you're getting crit hits out frequently enough. the dual attack Critical Strike might help there, as well as being pretty good for energy management.

I'll leave you to work out the details, hopefully I've given you a few possible ideas. You've inspired me to look into an assassin degen build, so I might go off and work out the details of that.