it started out innocently. one of the very few interesting results of the rules of the game is that you need a monopoly to improve properties. but at the beginning of the game, before you really have a sense where things are going, you'll pick up properties at random. so at first, you start solving this with very lucrative exchanges- the final property in your monopoly for the final property in theirs. but this is clunky- what if one property is obviously much better than another? we would solve this by trading more than one, or by having some cash alongside, but eventually i was having a hard time arranging such a trade with one of the other players, and it hit me that we could just trade properties, but swap the rents. so you'd both have a monopoly, but you could keep the same effective rent composition
once you have the idea there are lots of places to take it. it effectively totally decouples portfolios from monopolies- with the suitable agreements (tracked in a notebook, by convention, by the banker) it becomes possible to effectively own individual properties without the rest of their monopolies. this is especially helpful when falling like vultures on a nearly fallen player. rather than allowing them to fall to 0 and get their properties auctioned off, possibly breaking valuable monopolies, they can just conduct the auction while still in the game, except handing out rent rights rather than the properties themselves
but now you often wind up in a situation where a player is still "in the game" but owns effectively 0 properties. this is an undesirable state to be in, but to me a wonderful state for my fellow players to be in, because i love playing the heel. so id do this for it's own sake, paying premiums to buy the rent rights off everyone else to completely monopolize a player. we quickly started trading fractional rent rights (often in exchange for giving up house rights) and i enjoyed trying to get a web of contracts with everyone such that all of someones rent would go to me, but from as many sources as possible. basically just to maximize how difficult it was to figure out that something like 80% of all the rent was going to me. i achieved this once, with 4 rent payments in a row getting split and passed around various ways before eventually winding up entirely in my pocket, before they stopped playing monopoly with me. which, fair
