1) Depends on how you define "kill". All Indestructible means is that "destroy" effects are ignored. This includes the SBA that destroys a creature when it has lethal damage marked on it. Every other way to remove that permanent functions quite normally - exile, bounce, sacrifice, reducing toughness, etc. It's hard to give an exhaustive list because there are so many ways to get a card off the battlefield.
2) No, because protection from a color prevents damage from sources of that color.
If I have an indestructible creature, what CAN and CANNOT kill it?
It will not care about any effects that use the word "destroy", how much damage it has marked on it or whether damage from a source with deathtouch is dealt to it. Anything that would result in the creature being [u]destroyed[/c] is meaningless to an indestructible creature.
Anything else works as normal. It can go to the graveyard by being sacrificed or by having its toughness reduced to 0 or less. "Exile" will still move it to the exile zone.
oh are you sure? because I thought protection means it cannot be the TARGET of spells. Neither of those target anything such as Day of Judgment.
It also means that. Protection does several things. Protection from X means that the object cannot be:
Damaged by X;
Blocked by X;
Enchanted, equipped, or fortified by X;
Targeted by X.
Day of Judgement does none of these things, so protection from white doesn't help against Day of Judgement. But Pyroclasm deals damage, so protection from red saves your creature there.
And I mean, like if I lightning bolt an indestructible creature, or pyroclasm it, will it be sent to the graveyard?
No. Damage does not send a creature to the graveyard directly. Damage (if it's greater than or equal to the creature's toughness) causes a creature to be destroyed. That destruction sends the creature to the graveyard. Since the destruction is ignored, ordinary damage is ineffective against indestructible creatures. Note that the damage is still dealt - it's not prevented in any way - the creature just doesn't care.
Protection stops Damage, Equiping/Enchanting, Blocking, and Targeting. Kor firewalker cannot be damaged, equipped, enchanted, blocked, or targeted by anything red. While Pyroclasm does not target, it does damage, which is prevented to the Firewalker. However, Obliterate does not Damage/Enchant/Block/Target, so it will kill Firewalker.
First one is: If I have an indestructible creature, what CAN and CANNOT kill it?
I need more understanding on this.
Second one: If I have a creature that has protection from red, such as Kor Firewalker, will Pyroclasm or Slagstorm effect it?
ALSO: How does Safe passage work? Do I cast it before they cast damage spells or attack, OR do I do it on the stack?
Please give me explanations regarding these.
Thank you.
2) No, because protection from a color prevents damage from sources of that color.
And I mean, like if I lightning bolt an indestructible creature, or pyroclasm it, will it be sent to the graveyard?
It will not care about any effects that use the word "destroy", how much damage it has marked on it or whether damage from a source with deathtouch is dealt to it. Anything that would result in the creature being [u]destroyed[/c] is meaningless to an indestructible creature.
Anything else works as normal. It can go to the graveyard by being sacrificed or by having its toughness reduced to 0 or less. "Exile" will still move it to the exile zone.
The damage those cards would deal to that creature will all be prevented.
"Protection from [quality]" does these 4 things, abbreviated "DEBT":
http://mtg.wikia.com/wiki/Indestructible
http://mtg.wikia.com/wiki/Protection
G Pumped Elvish Warriors G
GW Infectious Slivers WG
WU Milling Allies UW
Legacy:
UB Hex-Depths BU (combo-control)
G NO/Aggro Elves G
Commander:
WUBRG Sliver Army GRBUW (multiplayer)
WUG Rafiq the Exalted GUW (1-on-1 voltron)
GU Edric's Circus UG (multiplayer tokens)
B Relentless Rats B (multiplayer combo)
UB Sygg, the Punisher (in progress)BU
UBR Nicol Bolas, Elder Dragon Highlander RBU (in progress)
Damaged by X;
Blocked by X;
Enchanted, equipped, or fortified by X;
Targeted by X.
Day of Judgement does none of these things, so protection from white doesn't help against Day of Judgement. But Pyroclasm deals damage, so protection from red saves your creature there.
No. Damage does not send a creature to the graveyard directly. Damage (if it's greater than or equal to the creature's toughness) causes a creature to be destroyed. That destruction sends the creature to the graveyard. Since the destruction is ignored, ordinary damage is ineffective against indestructible creatures. Note that the damage is still dealt - it's not prevented in any way - the creature just doesn't care.
Indestructible means it cannot be destroyed by lethal damage, nor destroy effects. Lightning Bolt cannot normally kill an indestructible creature, nor can Doom Blade or Day of Judgment. Grasp of Darkness and Path to Exile can, because they don't destroy.
The latest Comprehensive Rules are also good, and can be found here.