I made a card game with some help from friends. Its called "cards with rules."
Everyone gets the same number of cards (dealer decides)
The remainder of the deck is placed in the middle and the top card is laid face up that number is the "rule card."
Anyone who plays that number gets to make up a rule. (it has to be a fair rule not like "I win") the majority can decide a rule is not fair but they have to dispute the rule based off fairness not just because they don't like it. ( So "i get to play 2 cards next turn" could be disputed, but "Everyone gets to play 2 cards next turn" would be fine or "if you play a 7 you can play any other card" )
some classic rules: if you have to pick up cards you have to pick up 3, or if you play a 7 skip the next person's turn, or if you play a face card you can place any card, you can play all the cards of the same number as long as the first one matches suit, If you play a face card you have to drink, If you say any word starting with the letter S you have to pick up 2 cards, all the rules are gone
You play any number or suit that matches the last card played, If you cannot play you pick up one from the deck. If the deck runs out the face up cards (except the last one played) are shuffled.
Rules must be enforced before the next person plays. trying to dodge a rule is fair play.
The first person out of cards wins.

I wanna make a board game one day.

Dead-ass.

Oh, that, and maybe a TTRPG as well.

Idk.