This is essentially a combo deck, but all the combo pieces are pretty playable outside the context of the combo. In addition, they are all Adventures where both sides of the card are decent, representing inherent card advantage - we're playing almost all our cards at least twice.

The core of the deck is

Lucky Clover

Copies our card draw, removal and ramp

Foulmire Knight

Draws us cards, blocks, forms part of the combo. Good early blocker

Murderous Rider

It's good card - who knew. It's even better when copied, just don't kill yourself with it. Also part of the combo

Order of Midnight

Gets our combo pieces back from the graveyard. Also better when copied and part the combo

Smitten Swordmaster

The key combo piece. Drains the opponent when you have knights out. Devastatingly good when copied. Is also part of the combo when on the board

Lovestruck Beast

Good blocker. Can be enabled by Foulmire Knight and Innkeeper

Edgewall Innkeeper

Draws us cards. Often feels like the worst card in the deck but can also draw a ton of cards and allow you to combo off in one big turn

Beanstalk Giant

Ramp that can be copied. Read that again. Early versions of the deck played Rosewall Acolyte, which could allow you to finish turn 3 with 7 lands on the board. Theoretically I believe 9 or even more is possible. Thinning the deck to that extent allied to huge card draw potential leads to big combo turns. Also has a decent body when you have 10+ lands down

Reaper of Night

More payoff than anything else. Copying this on turn 4 buys you the time to really put your combo together. It's kind of sweet on Arena watching your opponent carefully decide which of his 4 cards to discard only to be hit by the copy and lose the other 2. The only evasive body we have, which sometimes matters

Once Upon a Time

Digs 5 deep for every other card in the deck apart from Clover and Trophy. Insanely good

Assassin's Trophy

We're Golgari, so why not? Can kill anything Murderous Rider can't

Lands

Possibly needs 1-2 more Swamps over Forests without Acolyte, combo turns can be very Black mana intensive

The Plan

Get Clover down, draw cards, ramp, then vomit Knights onto the board and copy Curry Favor (That's Smitten Swordmaster's Adventure). Works surprisingly well even against competitve decks. If it doesn't work, beatdown with a Giant or Reaper.