Hey Mark. I was just thinking, lots of players complain about the "once per turn effect", but at least I very rarely hear players complain about the very similar "tap as a cost to activate ability". Of course, there is a very teal functional difference; plenty of cards untap other permanents, yet nothing (that i know of) overrides the "once per turn" effect. Do you think untap effects were a mistake? In the same vein as reclaiming arbitrary cards from exile.

I do not consider that a mistake.

Do you think that "to cast X spells or activate abilities of X" will ever be templated?

With the right set, sure.

can i request more activated abilities that activate from hand/graveyard?

We will do more, but they both want to be done with a light touch.

"Red can temporarily copy things, and green (with certain restrictions) can copy its own creatures."Doesn't White also make copies, with effects like populate or effects like Preston the Vanisher? Also, Black likes to make copies of dead/exiled creatures, usually making them different creature types (ie Sauron, the Necromancer/Kinzu of the Bleak Coven/Activated Sleeper)

White can, in certain circumstances, copy token creatures, and black sometimes uses copy technology in reanimation. Both are very limited though in their use of copying.

I was interested to see that Saddle can only be activated at ‘Sorcery Speed’. If you could go back, would you have made Crew function the same way? I would have expected the two to work similarly. I guess with how the mounts are functioning, being able to activate it at instant speed is kind of meaningless, except I suppose to Saddle in response to removal.

We need crew to function that way because we want Vehicles to be able to block. Saddled creatures can naturally do that, and the effects we want for saddle are more offensive in nature.

We've seen several cards that give spells flash or otherwise let you cast them as though they had flash, but if/when a card that lets you activate abilities as though they didn't have "Activate only as a sorcery."?

If. Messing with safety valves can be dangerous.

If or when: An old mono artifact getting re-errataed to have 'you may only activate once per turn' instead of tapping.

That’s a big if. I don’t see the need to change it.

Hi Mark! When initially designing planeswalkers back in Lorwyn, why did they not tap to activate? Given that they only activate once per turn and there is an in built way in the game of MTG to represent once per turn abilities, it seems like a deliberate design choice to not have them tap. This would make it unambiguous when walkers have activated for turn as well as give some interesting synergy with untappers.

We didn’t want players to untap planeswalkers to use their abilities again.

The line "activate only as a sorcery" reads so clunky and inelegant(just like this question) have you guys ever looked into keywording or streamlining it?

We’ve looked into other templates.

More and more often, it seems like things are being restricted to “only activate as a sorcery”. Personally, I find this to be detrimental to having fun during limited or even constructed, and feel like there’s less interactivity than there has been in previous sets. Is this a complexity issue of some kind, or has there just been more activated abilities recently?

Restrictions are a core tenet of good game design. You give the players a goal and then give them obstacles to that goal. Game designers then use those obstacles as a means to push players towards the better game play. Every ability being usable at “instant speed” might give the players more flexibility, but it doesn’t lead to better game play. Having to make difficult decisions to maximize the route to victory is the bread and butter of fun Magic. One final note, increased choices do not inherently lead to more interactivity. If I can always wait to use my abilities until the last moment, that more often decreases interactivity.