Briefly establish the key details of your characters and existing relationship (in any order):
Invent setting material — personal context, mutual acquaintances, &c. — as needed to detail the above.
Then, put three tokens in a bag — two rose, one stone. Draw one token each, without showing the other.
If you drew a rose, you are in Love with the other. If you drew a stone, you are not.
(If playing remotely, it may be easier to each flip a coin to decide. May God save your empty souls if you both get stones.)
Take turns writing letters. Whoever picked their token first writes first. Invent a suitable pretext for opening correspondence.
The letters must follow a strict pattern, set out in the “Letter-writing” section below. As you know, good society prides itself on its epistolary form.
Your third letter must be your last, or public speculation will become unbearable.
If you are in Love with the other, and you believe they reciprocate your affections, send a rose along with your third letter. (Digital roses are acceptable when accompanying digital letters.)
If you are not, or you're not sure, do not send a rose. (If you are the first player, this of course passes the question to the second player.)
If you receive a rose and you too are in Love with your correspondent, reply with a rose of your own, post haste!
If you receive a rose but you do not reciprocate your correspondent's affection, propriety obliges you to reply curtly and terminate contact as politely (but firmly) as possible.
Once any roses and responses have been sent, or if both players decline to send roses with their third letters, the game concludes. Proceed to the next section.
Reveal your tokens to each other. According to their types, evaluate whether you won or lost, as follows.
If you sent a rose to a stone, you lose, and are so embarrassed that you can never show your face in public again. (If you are the stone, you too are embarrassed and must withdraw from public life for a month.)
If no rose was sent, any rose players lose and must grieve accordingly — though they can take some solace in the fact that their social standing remains intact. Any stone players win, inasmuch as they ever can. (If you are both roses, it is likely that you will die of broken hearts at this point.)
If roses were exchanged between two rose players, then you win! May your Love bloom and flourish forever, or at least for as long as a rose will.
Recommended post-game exercise: Discuss what happened and why you made the decisions you did. Consider whether you communicated well or poorly, or if the outcome was just a quirk of fortune.
Choose as many as you like of the following sections, in an order that feels appropriate. Make other people and context up, as needed.
Other than as required by the inquiry and response sections (2 & 6), you may not refer to your correspondent in the text of the letter.
On no account should you make explicit your feelings toward your correspondent, nor toward any other potential romantic entanglement — even discreetly. If you do, both players lose and are so mortified by this flagrant display that they can never bring themselves to play the game again.