1) To Ritchie, is the premeditated act of pretending you want to hang out with someone when you have the ulterior motive to get them to do something for you; it is generally characterised by an outcome where the Ritchier makes a net benefit off the person Ritchied.
Lad 1: "Man, Dave invited me around for brews, so I brought a carton and when I got there he wanted me to help move his pool table... Fuck. I think I got Ritchied!?!"
Lad 2: "Yeah bro, you got Ritchied to the fucking nines!"
2) The act of delegating tasks more demanding than your own to achieve an outcome with the least effort.
Ritchie: "Okay guys, if you guys mow the lawn and I put away this salt shaker, we'll be able to start the BBQ in no time!"
(10 minutes later) ... fuck. Did we just get Ritchied?"
3) Ritchie-ing is also more successful whilst making oneself look busy doing other tasks (but actually not doing anything at all besides walking around quickly...)
Ritchier - in present tense, the one with the motives to, or, in past tense the one who has; pulled a Ritchie on you.
Ritchied - the victim of the Ritchie who came around with the best of intentions, to drink brews with his mate!