Draw

Card draw is a regular part of a player's draw step. It is also a mechanic that may lead to card advantage.

Description
A player draws a card by putting the top card of their library into their hand. Card drawing may also be done as part of a cost or effect of a spell or ability. If an effect moves cards from a player’s library to that player’s hand without using the word “draw”, the player has not drawn those cards. This makes a difference for abilities that trigger on drawing cards or that replace card draws, as well as if the player’s library is empty. The colors of the color pie make different use of card drawing. The mechanic is primary in blue, secondary in black and green and tertiary in white and red.

All colors

 * Cantrips: draw a card when playing a small spell, or a triggered ability of a permanent.
 * Cycling: discarding a card to draw or search for a card

Blue
Blue is the best at card drawing. It has the most of it and no restrictions. The hand and the library are a metaphor for knowledge (the former being what you currently are thinking of while the latter is the entirety of what you know), so card drawing is a perfect fit for blue.
 * Regular card draw: take some number of cards from your library and put them into your hand.
 * Card filtering: draw several cards, but you can't keep them all. The remaining cards go into the graveyard or are put onto the top or bottom of the library.
 * Looting: draw one or more cards, and then discard a number equal to what you drew. Looting almost always goes to the graveyard.
 * Curiosity: draw a card when a creature deals combat damage to another player.
 * Tutoring: search your library for a particular card.
 * Regrowing: return a card from your graveyard to your hand. In blue, this usually gets you back instants and sometimes sorceries.

Green
The color with the next most access to card drawing is green. Green uses card drawing as a metaphor for growth. Usually, green's card drawing is tied to its creatures or other aspects of board position.
 * Cantrips: while all colors can have creature cantrips, this is something done much more in green.
 * Regular card draw: Most green card drawing ties directly into one or more of its creatures. Green draw spells often take the form of conditional card draw, i.e. "Draw a card for each..." or "Draw cards equal to...".
 * Curiosity: green is secondary in this ability.
 * Tutoring: other than lands (see below), green tutors only for creature cards.
 * Regrowing: green is primary in the ability to get back any type of card from the graveyard.
 * Land fetching: green can draw specific lands.

Black
Black is third in card drawing. It always involves paying some cost. The flavor of card drawing in black is that of greed or bloodletting, while the flavor of tutoring in black is one of demonic knowledge.
 * Regular card draw: black's card drawing always comes with an additional cost (paying life, sacrificing).
 * Tutoring: black, along with blue, is the color that can tutor for any card from the library.
 * Regrowing: black has the ability to put creature cards from its graveyard into its hand or on the battlefield (Reanimation).

Red
Red is number four in card drawing, it doesn't do a lot. R&D made the conscious choice to limit red’s straightforward drawing on an empty hand. Red cards related to card draw generally have a flavor of fate or randomness. Red doesn't get any card advantage, with two exceptions—impulsive draw and wheeling.
 * Looting: red has its own form of looting, what R&D calls "red looting" and many players call rummaging, where it discards before it draws. Spells that begin by having one or more players discard their hand, then draw some cards are almost exclusively the province of red.
 * Wheel effects: these effects causes each player to discard their hand and draw a completely new one, most frequently either seven cards or a number of cards equal to the number of cards discarded.
 * Regrowing: red sometimes can regrow sorceries. Second, some direct damage spells have conditions by which the player can get them back from the graveyard. Third, red has Phoenixes that can return themselves.
 * Impulsive draw: red gets to draw cards (technically, it exiles them) but only has access to cast them for the rest of the turn. The cards that are not cast remain lost in exile. R&D sometimes refers to this as the "Elkin ability", referring to Elkin Bottle. Some of the higher-power cards grant the ability to cast until the end of one's next turn, allowing for a turn with all untapped lands.

White
There are very few monowhite draw spells. It used to be focused on having to use a specific strategy. As of 2020, R&D worked to give white more card draw to help solve its problems in Commander.
 * Tutoring: white can occasionally tutor for enchantments and less often for artifacts, usually Equipment.
 * Regrowing: white can get back artifacts and enchantments from the graveyard. It can also reanimate small creatures.
 * Symmetrical draw: white has been allowed giving card draw (up to three cards) to the player and an opponent. Currently has only been cantrip-based, but will get more.
 * Cantrip engines: white has many permanents that turn a particular subset of cards into cantrips, as part of rewarding a specific focus.
 * Rule-setting draw: Since white can set rules, if an opponent breaks those rules you may draw a card (eg. Mangara, the Diplomat).