A portmanteau of win condition, in a collectible trading card game (such as Magic: The Gathering or Yu-Gi-Oh!) a wincon is the particular method one intends to use to become victorious and can range anywhere from a specific two (or more) card combo to any one of various types of combat damage, amongst so many more. There are even cards that explicitly state that if such and such is true then "you win the game."
A vital and necessary part of deck building, it can be overlooked by those new to the game as it can be confused with either strategy, theme, or both. Throw in terms like nonbo, synergy, and archetype, and many a noob will just stop and stare, mouth agape.
Wincon also refers to a series of British science fiction conventions that took place between 1988 and 1999, but who knows what the future holds?
Just for a final bit of clarity: wincon currently has no relations to Microsoft Windows or its fans or conventions, or to the verb, defenestrate.
Brevity Quest 2024
(tweaked for both
Glowing Fish and passalidae)