Magic: The Gathering

Magic: The Gathering - is a tabletop traiding card game that involves luck, skill, politics, and, sometimes, fun. Can be played with more than 2 players, and offline.

Cockatrice
Cockatrice is a virtual tabletop for mtg without enforcing rules, usual go-to way to play mtg with other members of community.

Resources for Cockatrice

 * Jumpstart Deck Generator by draftsim.com
 * dr4ft.info - drafting simulator.

Other ways to play MTG

 * XMage - virtual tabletop with rule-enforcement, has an advantage of ability to play online with random people.
 * Tabletop Simulator - popular universal virtual tabletop for any tabletop game, has an advantage of ability to play any other game than mtg, and using tabletop sandbox tools.
 * Untap.in - online virtual tabletop, free but heavy on resources, playable on Android, with rule-enforcement.