'Magic: The Gathering' (by Richard Garfield, 1993) is one of the most extraordinary games I have ever played. You can find all about this fantasy based collectible trading card game on the 'Wizards of the Coast' website.
The concept of the game is 2 wizards battling each other through turn-based attack and defense. This mainly happens by means of creature mobilization (whereby each creature's capabilities depend on their activation cost, composed of differently typed resource requirements) and spell casting, which may temporarily/dynamically alter the game environment (e.g. flying creatures lose their flying ability). The great variety of cards (via multiple extension sets per year) and progressive introduction of new game mechanics make this an extremely challenging game.
The most comprehensive Magic: The Gathering tutorial I could find takes less than 30 minutes of your time: Card Kingdom's tutorial on YouTube.
A lot of the joy comes from deck construction and tuning through playtesting. This is a highly creative process, including multiple complex trade-offs of both strategic and tactical importance. On the one hand, low-economy card decks usually are more efficient, since the probability of drawing the right card at the right time increases. On the other hand, these decks are less versatile because of their reduced resistance against the multitude of hidden strategies in yet unkown opposing (tournament) decks. Also, decks based on a consistent theme (i.e. composed of easily interacting cards) generally have a greater chance of success.
I happily witnessed The Old Days, and (after a 15 years break !) I'm now most definitely enjoying The New Days. My 'Planeswalker Points' represent my sparse official tourney results (2013 Results, 2014 Results, etc.). Nowadays, I stick to the 'limited' format, playing all prerelease Sealed Deck events plus a weekly Booster Draft. That also nicely fits my full sets singles collection goal.
In 2014, I wrote software to capture deck construction reasoning, also visualizing the deck's statistics impact of sideboarding against specific matchups, so that decks could get further improved (especially towards competitive play). This resulted in the following stand-alone generated website, for practical reasons uploaded to my personal website (i.e. one-way menu based navigation only). This collection of decks was meant to keep growing over time, potentially including work from other deck authors (on simple request), but I stopped playing constructed formats, as mentioned above. Enjoy anyway !
Hint: follow the 'Help' hyperlink at the top right corner of any generated HTML page to get an idea on how to specify any deck (example included).
In 2016/2017, I wrote software extending the official Gatherer search engine with extensive (approximately 1000) pre-defined filters, clustered around game concepts. Keeping these filters up to date upon new set releases ensures continued support whenever strategizing the respective play formats. This resulted in the following stand-alone generated website. Enjoy !