- This article is about the about the ability Defender. For the player, see Defending player.
Defender is a static ability that renders a creature unable to attack. The keyword was introduced as a replacement of the baggage that the creature type Wall carried. It was introduced with Champions of Kamigawa and was retroactively added to all Walls. 
Before defender was introduced all Walls were unable to attack as a definition of their creature type. Now creatures with Defender can potentially lose the ability and attack - this would have been a rules-hassle before. However, Defender has introduced some confusion as well, because not all cards that refer to Walls or non-Walls have been changed.
It is perfectly legal to choose a non-Wall creature with Defender, such as Carven Caryatid, even though that was not the original intent.
This ability is clearly designed to work on non-Defenders, but that is not the case. It is legal for Norritt to target any non-Wall creatures with Defender, such as Carven Caryatid.
- Changing a creature's type no longer affects whether it can attack. A Wall that becomes a non-Wall will still have the defender ability. Likewise, a non-Wall that becomes a Wall won't have the defender ability.
The latest reminder text for Defender reads "This creature can't attack."
Cards that grant defender
- Gelid Shackles ( to grant defender until end of turn)
- Guard Duty (Aura)
- Guardian Zendikon (Land becomes a 2/6 wall with defender)
- Dormant Sliver (all Sliver creatures)
- Peregrine Mask (equip , also grants flying and first strike)
Cards that circumvent defender
Creatures with defender that may be able to attack
- Ageless Sentinels (after it blocks)
- Colossus of Akros (if it's monstrous)
- Dark Maze (exiled afterwards)
- Elder Land Wurm (after it blocks)
- Gargoyle Sentinel (: until end of turn, also gains flying)
- Grozoth (: until end of turn)
- Guardian of the Ages (after you're attacked, also gains trample)
- Loyal Gyrfalcon (until end of turn, when you cast a white spell)
- Manor Gargoyle (: until end of turn, also gains flying)
- Mirror Wall (: this turn)
- Mistform Wall (: until end of turn, also becomes some non-Wall creature type)
- Mobile Fort (: until end of turn, also gets +3/+1)
- Nivix Cyclops (until end of turn when you cast an instant or sorcery, also gets +3/+0)
- Ogre Jailbreaker (if you control a Gate)
- Pillar of War (if it's enchanted)
- Prison Barricade (if it was kicked for , also gets a +1/+1 counter)
- Returned Phalanx (: until end of turn)
- Sentry Oak (until end of turn if you win a clash with an opponent, also gets +2/+0)
- Shoal Serpent (until end of turn when a land enters the battlefield under your control)
- Slithering Shade (if your hand is empty)
- Spire Serpent (if you control 3 or more artifacts, also gets +2/+2)
- Tidewater Minion (: until end of turn)
- Torpid Moloch (sacrifice 3 lands: until end of turn)
- Vodalian War Machine (tap a Merfolk creature you control: until end of turn)
- Wakestone Gargoyle (: all your defenders until end of turn)
- Walking Wall (: until end of turn, also gets +3/-1)
- Wall of Wonder (: until end of turn, also gets +4/-4)
- Woolly Razorback (if it's blocked at least three times)