July 17th 2009 - 249 cards

In addition to new cards about half of the cards are reprints, Magic 2010 (or M10 for short) marks a major shift in the way Wizards of the Coast produces the "Core" set.

Another important marketing change is that starting with Magic 2010, Wizards of the Coast will release a new core set every year, instead of every two years, as it has done since 1995.

Wizards decided to introduce new cards into M10 (which comprise somewhat less than half of the set, with the remainder being reprints) so that the Core set could serve as a true introduction to the game, instead of a collection of recent notable cards.

M10 is the first core set to include "mythic rares" as well as the first core set to include planeswalkers, a relatively new card type which was first introduced in 2007. All five of the initial set of planeswalkers from the Lorwyn Expansion are reprinted in M10 as mythic rares.

Wizards of the Coast has also overhauled the core ruleswith the introduction of Magic 2010. The changes included the renaming of several zones and actions of the game, eliminate the 'mana burn' aspect of the game and, more relevant for gameplay, an alteration to the way combat damage is assigned. This was the first major alteration of the game rules since the introduction of rules in 1999, and was instituted to make the game more streamlined and intuitive; previous damage-assignment rules, for instance, would allow a creature to, in the words of Rules Manager Mark Gottlieb, "swing its fist to punch, vanish from the battlefield, and [still] have that punch land."