In Magic, is the player going first advantaged?
The game balances first player advantage because the start player does not draw a card at the beginning of his first turn, but the second player does draw a card during his first turn.

The rule that says it is this one:


  103.7a In a two-player game, the player who plays first skips the draw step (see rule 504, “Draw Step”) of his or her first turn.


While this does balance the game somewhat, this article by Florian Koch shows that the start player still has a small statistical advantage. Koch points out that other factors could influence the results, including the skill level of the players and the decks being played (including knowledge of what deck your opponent is playing).

In case you didn't know, if you win the coin toss (or dice roll) it doesn't mean you have to begin, it means you decide whether you want to begin. There are players who actually don't want to begin; some decks prefer the extra card instead of the turn advantage.