"...Play TFolpoly!!!" your girlfriend said as she pulled out a board game from outside of your peripheral vision
"Why?" You asked
"Well, it's not trying to get sued by Hasbro I think." your girlfriend said teasingly and she entered your home as you gave her a look "Alright, saw it at this random shop and thought YOU'D like it." In a sort of truth or dare game she asked you what your fetish was and transformation was your answer. You had to qualify that a bit especially since it wasn't every single transformation and, well she was still your girlfriend at the end of it.
"Fine," you said as the two of you went to the living room "guess we can put something on in the background and have some fun with a gimmick monopoly rip off." Really it was you setting up the game as your girlfriend put some random rom com shlock in the background. Ok shlock was a harsh word but you didn't care about the one she put on. Meanwhile this board game was pretty well made. The folding board had some weight and actual wood instead of cardboard, it seemed like the mostly blank pattern in the middle was filled with weird runes. Instead of names of real estates there were... You checked out what was Mediterranean Avenue and saw that it read "Inanimate" and Baltic was "Animal" Taking a quick look in the explanation in the rules...
"It's monopoly rules, just look them up on google or in the copy you probably have in whatever passes for your game cabinet. You play as wizards and witches going around magical leylines that you bribe the fae around with money to gain control of. Each color represents an element of transformation, and each leyline represents an element of that element of transformation. When you gain a Monopoly all leylines gain a boost. Enjoy the game!"
"Kinda cute booklet" you said "anyways it's just monopoly so" You dealt 1500 to yourself and your girlfriend, put the chance cards and community chest on the board and decided to roll the dice. Your girlfriend let you go first and you found you landed on a "Change" space, drew a card, and read aloud "Fey gift you 50 dollars" so you took 50 bucks from the bank and put the card on the bottom of the pile.
"Riveting" your girlfriend said as she rolled the dice and got a 9 "I'm in the lead, and getting a card" She landed on a "Physical" space of what looked like a "youthening" group. Your girlfriend chuckled
"I guess now I'm the Witch of making things younger. Perhaps you'd like a young lady ten years younger than you?" she teased as a mental idea popped up in both of your heads
"That'd make you 8 now if..." you looked and your girlfriend looked to see her newly adult body cross the boundary and become "not quite adult" and then "not quite a teen", "not quite a tween", and now a child of 8 or so. She was draped in her clothing looking highly concerned.
"I guess this game's real?" You said questioning
"I just thought of becoming younger an-"
"Don't think of becoming younger!" you warned "you only have the physical youthening leyline. I don't think using it any further is going to be a good thing."
"Well I don't want to become a-" she cut herself off "you know..."
You said "Well, there may be some hidden rules about the TF parts of this game. Looks like you may be able to youthen yourself at will, and if I had to guess anyone who steps onto that property. Now what we need is for you to get older."