Frequently Asked Questions
Q: Can I use the activated ability of Mishra's Factory Buy to pump itself the turn it is brought into play?
From Ruling G.37.2 - Creatures with "summoning sickness" cannot attack, and they cannot use any of their own abilities which have a tap symbol in the activation cost. Non-creatures are unaffected by summoning sickness. [CompRules 1999/04/23]
When Mishra's Factory Buy isn't animated, you may use it's ability to provide one colorless mana or to give an Assembly Worker +1/+1 whenever you wish (regardless of whether you controlled it since the beginning of the turn). As soon as you animate it, though, the rules for using the activated abilities of a creature apply, and you can no longer use Mishra's Factory for it's mana or pump abilities if it has "summoning sickness".
It is common for players to animate a Mishra's Factory, declare it a blocker, and then tap it to give itself +1/+1 - essentially giving them an uncounterable 3/3 blocker for the cost of a single mana and land drop. This pump-play is not possible unless they have controlled it since the beginning of the turn. Having another Factory in play that isn't animated or doesn't have summoning sickness works, though.
Official Card Rulings (Current as of 1/16/2004)
When it is an Assembly-Worker, it is still a land and retains all of its other abilities. [Duelist Magazine #2, Page 14] When animated into an Assembly-Worker, it has creature type Assembly-Worker. [D'Angelo 2001/08/31] The card name does not change. It remains "Mishra's Factory". [Jordan 2003/06/14] The Assembly-Worker is an artifact creature only until the end of the turn, and then any Enchant Creature or Enchant Artifact spells on it are put into the graveyard. [Duelist Magazine #2, Page 15] It can attack on the turn an Assembly-Worker is created, but it may not attack on the turn the land itself is brought into play. See Ruling G19.27. [Duelist Magazine #2, Page 15] Any counters on the Assembly-Worker remain even if the counters stop being meaningful when it de-animates. [D'Angelo 1998/02/03] An Assembly-Worker is considered to have a zero mana cost. [Duelist Magazine #5, Page 14] Tapping a land for something other than mana is not a mana ability. [D'Angelo 1999/10/01] The ability to turn it into an Assembly-Worker can be used while it is an Assembly-Worker and will reset the initial power/toughness to 2/2, but this will not override temporary effects such as Sorceress Queen Buy. [D'Angelo 1998/05/28] When it is an Assembly-Worker, it is an artifact and can therefore be affected by spells and abilities that affect artifacts, such as Disenchant Buy. [WotC Rules Team 1995/02/09] If another player takes control of this card while it is an Assembly-Worker, using Aladdin Buy for example, that player keeps control until the control effect ends. They do not lose control just because the card stops being an Assembly-Worker. [WotC Rules Team 1995/02/09] Note that enchantments which steal cards (such as Control Magic Buy and Steal Artifact Buy) do go to the graveyard if the permanent they enchant is no longer valid. If an Assembly-Worker is changed to another land type by something like Phantasmal Terrain Buy, it will stay a 2/2 artifact creature and keep the creature type "Assembly-Worker" (until end of turn), but it will change its land type as directed. [Jordan 2003/06/14] Extended tournaments (see Ruling 803) have banned this card since 1999/10/01. Note - Also see Changing a Permanent's Type, Ruling 212.1c. Note - The Antiquities card appears in four different versions with different art. Three of the cards were each U1 rarity and one was C1 rarity.