Gimmicky

Chandler card art. Looks like he's selling a gimmick. (And RIP, Matthew Perry.)

Some Magic decks are more 'gimmicky' than others. This post explores that concept and provides examples.

Exploring the Concept

Dictionaries (like this one) tend to define 'gimmick' as "a trick or device used to attract business or attention," "an ingenious and usually new scheme or angle," or simply "a catch."

In Magic, players use the term to mean something a little different. From Reddit: "Gimmicks in ccgs tend to be the label for strategies that rely on your opponent's unfamiliarity, unpreparedness, or just plain luck to win. It's like a "fool me once" or "all-in" type of thing." Later in that post, another argues that a gimmick deck is "a deck whose sole win condition relies on 1 or 2 cards." 

I would define a gimmick Magic deck as one that has two characteristics:

1. it has an 'unorthodox' and single/narrow/focused/inflexible win condition
• it does this (but nothing else) very well: it has little means to counter or adjust to opponents' strategies
• it is overly reliant on one card or combo or mechanic
• it often relies on an unusual ability (one that features only in one set or on a few cards all-time)
2. relies on surprise (it is easily defeated once the opponent expects it) 

Basically, a gimmick deck brings Nelson (of Simpsons fame) to my mind. 

The person who wins with such a deck does so with a smirk: "haha, got you!" Then they have to put the deck away because it will be expected and easily defeated next time. Thus, per a coolstuffinc article, "Gimmicks are best used sparingly else fans will tire of them."

Examples

Dimir Rats

This deck relies on two cards: Tetsuko and Rat Colony. The latter violates the "four copies" restriction in its text, enabling you to have as many Rat Colony cards in your desk as you wish. And they get stronger for each one you have on the battlefield. Get out as many rats as possible with card draw spells, then make them unblockable with Tetsuko. 

20 Rat Colony (DAR) 101

4 Tetsuko Umezawa, Fugitive (DAR) 69

4 Negate (M20) 69

4 Opt (DAR) 60

2 Cancel (M21) 46

2 Divination (DAR) 52

2 Thirst for Discovery (VOW) 85

8 Swamp (BRO) 273

8 Island (BRO) 271

4 Drowned Catacomb (XLN) 253

1 Shipwreck Marsh (MID) 267

1 Watery Grave (GRN) 259

Rune for Improvement

This is less of a gimmick deck because it requires a few cards (and has a few means to adjust to opponents' strategies), but the heart of a gimmick is there. For this to be viable, you need Runeforge Champion and Jukai Naturalist (and a bunch of rune cards, which is an enchantment subtype that appeared only in Kaldheim). The Champion makes runes cost 1, Jukai drops that to zero, and the runes themselves let you draw a card, making it possible for this deck to really take off.

4 Runeforge Champion (KHM) 26

4 Rune of Might (KHM) 191

4 Rune of Sustenance (KHM) 25

4 Rune of Speed (KHM) 148

4 Jukai Naturalist (NEO) 225

2 Tamiyo's Safekeeping (NEO) 211

4 Hallowed Haunting (VOW) 17

2 Borrowed Time (MID) 6

1 Showdown of the Skalds (KHM) 229

4 Michiko's Reign of Truth (NEO) 29

4 Generous Visitor (NEO) 185

7 Plains (SLD) 359

4 Cragcrown Pathway (ZNR) 261

4 Branchloft Pathway (ZNR) 258

1 Needleverge Pathway (ZNR) 263

1 Sundown Pass (VOW) 266

1 Mountain (SLD) 362

3 Forest (SLD) 363

2 Rockfall Vale (MID) 266

Zenith Flare

The Ikoria set (2020) featured the cycling mechanic. One deck I saw a lot during this time featured a bunch of cards with cycling (47 appeared in the set) and finished off an opponent with Zenith Flare. If you saw it coming, and had a way to counter Zenith Flare, you were fine.

Concluding Thought

There isn't, technically, anything wrong with a gimmick deck. But a key part of the game is enjoying the game, so if you run decks like this, be prepared for that initial "you got me" followed by "okay, can you play a real deck now?"