Original Interrupt

[PhilipJFry]

OK, my brain has been forever tainted by the stack, and now I can no longer adequately explain why Magic had Interrupts.  I was trying to explain to my wife why her Force of Will is printed as an Interrupt, but her 8th Edition Merchant Scroll can still grab it.  That led to a discussion of how original timing rules worked with Interrupts - oh, and also led to me trying to explain why her Mystical Tutor from Mirage cannot grab Black Lotus if we talk about Lotus as a "mana source." 

Anyways, can someone give me a brief refresher on how the timing system for Magic originally worked and why it necessitated that Counters and cards that prvided mana be "Interrupts?"  Thanks!

[dangerlinto]

Interrupts were like an end-cap for the batch (the proto-stack).  You could Healing Salve (instant), then, if I counterspelled (interrupt), you could not respond with another spell (say another healing salve), unless it was an interrupt (another counterspell).

Why they really thought they needed interrupts is really not much more than an early design decision based on flavour.  An interrupt was "faster" than a instant.  The only useful part was it kept unnecessarily long batches from occuring with counterpells in them, the way that can happen now.

My memory of Mana Source is fuzzy.  The term "mana source" was only around for a short while.  It appeared on cards like Dark Ritual, and worked as if they had the speed of a mana source - that is, you could not respond to them, if I recall correctly.  THis was obstensibly, to keep people aware that you could not respond to a mana source -  there were certainly enogh people back in the day who thought that when I tapped a land for mana, you could tap it with Icy Manipulator to keep that mana from occuring.... which was wrong on so many accounts it's not funny.

[GrandpaBelcher]

Basically, Interrupts could only be responded to with other Interrupts.  So you could Counterspell someone's Force of Will, but you couldn't Lightning Bolt their dude in the middle of a counter war.  All interrupts resolved in a group, then more could be played, which had to resolve before Instants could be played.  These were called batches.  It was crazy.  Thank Wizards for the stack.

Mana Sources were played at interrupt speed and were uncounterable.  Mystical Tutor could never go get a Black Lotus, which was always considered an Artifact (although some Hulk Flash player tried to get a Breeding Pool with it against me this weekend).

A good way to refresh yourself would be to get the Microprose Magic and Spells of the Ancients computer games off The Underdogs, as it still used the old rules for Interrupts at least.

Or just read this:  http://www.wizards.com/default.asp?x=mtgcom/daily/bb27