This is somewhat related to Instants theme, but not completely the same thing.

Examples of ideas I've had so far for prediction / planning mechanics: (None of which are great, and certainly not for common)

Plan for Ambush

 

 C 

Instant

Set in Motion (: Exile this card face down from your hand with two time counters on it. At the beginning of your upkeep, remove a time counter. While it has exactly one time counter, you may cast it without paying its mana cost. Set in Motion only as a sorcery.)
If you control a Mountain or a Plains, target creature gets +1/+0 and gains first strike until end of turn.

Canny Major

 

 U 

Creature – Human Soldier

When Canny Major enters the battlefield, predict. (Choose a colour and a number.)
Whenever an opponent casts a spell with the predicted colour and converted mana cost, target creature you control gains protection from the predicted colour until end of turn.

2/2

Battlefield Tactician

 

 U 

Creature – Human Soldier

Whenever this creature attacks, bluff for instants. (Defending player chooses one: this creature gets +1/+1 until end of turn; or the next time you cast an instant spell this turn, this creature gets +2/+2 until end of turn.)

1/2

Over on the main cardset comments thread, Jack proposed (intending for people to riff on it):

> Plan (: Exile this facedown from your hand. Until the end of your next turn you may turn it face up and cast it for . If you don't, return it to your graveyard.)

I wondered if some sorceries could have the ability to use them during combat if you prepare them:

> Planning (: Exile this sorcery facedown from your hand. Until end of turn, you may cast it for any time you could cast an instant. If you don't, return it to your hand. Plan only as a sorcery.)

I then came up with Set in Motion as on Plan for Ambush, and then proposed:

> Manoeuvre (: Choose target creature and exile this card face down. While that creature is attacking [/in combat?] you may cast this card from exile for its manoeuvre cost. [Manoeuvre only as a sorcery.])

Jack proposed a long-term planning mechanic for big high-impact sorcery spells like Wraths:

> Mastermind 2-3 -- (Exile this face down. At the beginning of your upkeep put a time counter on it. If it has 2 or 3 time counters on it, you may cast it for its mastermind cost.)

On the Goblin Artisans review thread, Jenesis proposed:

> Coup d'Etat
> Sorcery (rare)
> Strategize (, Reveal this card from your hand: Exile a card from your hand face down. As long as that card has strategize, you may cast it from exile as though it had flash. Strategize only as a sorcery.)
> Destroy target creature. If that creature was legendary, its controller loses 3 life.

This is a twist on my Planning mechanic above. It's pretty interesting because it's not a discount mechanic - it charges you more to get to cast your sorceries with flash - but it allows you to bluff by exiling cards that don't even have strategize at all. On the flip side, it does require you to reveal the first one.

I can't remember we already proposed. Did we have something like, "Plan ahead (2: exile this card from your hand face down. You may cast it from exile, and if you do, draw a card. Plan ahead only as a sorcery. You can't cast it the same turn you exiled it.)"

That's very similar, but with a simpler restriction and simpler bonus, and we definitely considered several very similar things, but now I'm coming back to it. But I don't know if it's too much complication for too little benefit.

Hmm. No, I don't think we discussed that particular version. My attempted rephrasing:

> Plan ahead (: Exile this card from your hand face down. After the current turn ends you may cast it from exile. When you cast it this way, draw a card. Plan ahead only as a sorcery.)

So you're not getting to cast any more cards in one turn than you could do if you didn't Plan them, because you have to pay the mana cost, but you're increasing the card flow. Vitenka suggested incorporating a cantrip - that's a nice way to do it.

But I'm not sure that it particularly rewards predicting what your opponent will do. And it doesn't enable you to cast cards when you couldn't otherwise have done, either by discount or by changing speed. That could be easily added, though - we could easily tweak it to allow casting as flash, as a variation on Planning / Strategize.

Yeah. My logic was, firstly, that we'd had so much difficulty with mana reduction, maybe a different bonus for planning makes sense and "draw a card" (or flash) is simplest. And the planning would be, can you predict which card you'll need next turn, so you can plan that one now. Although that only works if you need your mana for something other than just "plan everything just in case". (There could be a use by the end of your next turn it or return it to hand/graveyard so you need to plan more precisely, but I think that would complicate it a lot.)

Crosslinking for reference: Link created Savvy Soldier as a suggestion for this mechanic:

Savvy Soldier

 

 C 

Creature – Human Soldier

Predict (If an opponent would cast a spell, first guess that spell's color and converted mana cost.)
Whenever you predict correctly, put a +1/+1 counter on Savvy Soldier.

1/1

It's one of the simplest possible implementations of "predict what your opponent's going to do", which definitely wins it some points. It's got the nice accumulating benefits that Contemptible Judge/Bribe Archivist/etc have, whereby they can all benefit from the trigger that any one of them provides (contrasted with things like Ainok Bond-Kin which costs enough mana you probably can't outlast multiple of them in a turn). I like that the CMC will often be guessable in the early game, and the colour will often be guessable, but guessing both may still be challenging enough to certainly not always trigger. It's possible it'd need a cost like though.

But anyway, yes, it's an interesting and direct enough solution to the problem that I should definitely give it some consideration.

It puts a "Hang on!" where one didn't used to be though - remember all the fuss of "Tap mana first then cast"? It's putting a step back in there - you have to interrupt your opponent in the middle of their casting something. Between them pulling the card from their hand and their saying what it is.

Better would be if you named it at the start of the turn, or something. More interesting bluffs that way too - but memory issues make it too messy for common.

You make a very good point. It probably does need to be something like

> At the beginning of each upkeep, predict. (Choose a colour and CMC.)
> Whenever an opponent casts a spell with the last predicted colour and CMC, put a +1/+1 counter on ~.

...Hmm, maybe that's staying a bit far from Link's suggestion. Let's try again:

> At the beginning of each upkeep, predict the colour and CMC of the next spell an opponent casts this turn.
> Whenever you predict correctly, put a +1/+1 counter on ~.

That could equally be "...predict. (Guess the colour and CMC of the next spell an opponent casts this turn.)"

Another tweak on the earlier exile-face-down suggestions that came up while I was thinking about Gefjun Disturber:

> Prepare (You may exile this face down for as a sorcery. If you do, on future turns you may cast it from exile for its prepare cost as if it had flash.)

Similar to Jack's Plan ahead, but giving up the cantrip for the opportunity to cast it for a reduced cost.

Another thought - Gustcloak as a mechanic for "Yeah, ok, that would be a bad idea, so we won't do that". Implemented as a rollback, but still gives the right 'sneaky planning' impression.

Interesting idea.

I think Gustcloak as printed before (eg Gustcloak Harrier) wouldn't actually be a good fit, because the opportunity to rollback is too early - people can just play their combat tricks afterwards. But that could be fixed by giving creatures the Reconnaissance ability instead.

I'll give it some thought.

Trying a different wording of the Prepare mechanic. It was:

> (You may exile this face down for as a sorcery. If you do, on future turns you may cast it from exile for its prepare cost as if it had flash.)

I'm now trying:

> ( as a sorcery: Exile this face down from your hand. On future turns you may cast it from exile for its prepare cost as if it had flash.)

That makes it clearer this is an activated ability. It's using the "activation restrictions on the left side of the colon" technology that the Goblin Artisans recently discovered.

However it might make people think they need to reveal the Prepare card from their hand to exile it, which would rather defeat the point. The "You may exile..." wording is more similar to Morph's wording, "(You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)".

So I ended up creating a cycle using Prepare, and some more as well. They play rather well. As I create more, one thing I'll need to ensure is that each colour has some that are useful in a range of circumstances, to keep the interest/mystery about what's the right course of action. Currently we have:

• Removal, useful at any time, especially in combat: Gefjun Disturber , Catastrophic Orders
• Useful in creature combat whether attacking or blocking: Prepare for Ambush , Prepare for Heroism , Mass Disguise , Synchronised Training
• Useful when a creature would die either in combat or to removal: Prepare for Survival , Blaze Luminous , Armour Under Clothes
• Useful when your creature is unblocked: Prepare for Infiltration , Return on the Other Side
• Useful when you're being attacked and have no blockers: Prepare for Readiness , Prepared Guardian , Point-Blank Airstrike , Zero Requiem
• Useful when you're tapped out: Supply Drop , plus all the -cost Prepare cards

My aim is to have each colour appear on at least two of those lines, if not three or more.

I want to make more prepare cards so there are some at all of common, uncommon and rare. It doesn't have to be a full cycle: Wizards these days prefer things to be unbalanced between colours to make the colours play differently from each other. But I do want several in at least black and white and probably red, and I think I'd like at least one more in blue too.

I have a couple of interesting decisions to make here. I had intended the basic land restrictions on the Prepare for Ambush cycle just to be enforcing playing them in-colour, and expecting the future ones would be monocolour with non-zero prepare closts and no conditions. But Vitenka interpreted the basic land restrictions differently: he took the pattern as being that every prepared card will have a condition to get the effect, often significantly harder to trigger, but the costs will be very low or zero. That strikes me as a fascinating idea, somewhat harder to meet and balance, but intriguing. I followed this pattern on Prepared Guardian.

Separately, I have another decision to make. The hybrid cycle are chosen to have mechanics that fit in the enemy colour pairs. They're currently free, and currently common. But they don't have to stay that way.
They could easily become uncommon and have the commons all cost some nonzero amount of mana to cast from exile. I'd want several more commons if so, but that's doable.
And the hybrid cycle don't need to stay free. I could easily give them all a prepare cost of a single hybrid mana and remove the basic land check.

I suspect I should make one or other of those changes; I suspect it's not sensible to have a common cycle of five cards that can all be free. Is it better to have the very flexible ones at common, or at uncommon?

Update 28-11-2016: Moved the hybrid free cycle to uncommon for now. Now I want to find at least one common prepare card for each monocolour. Currently there are three commons remaining: Blaze Luminous, Prepared Guardian, Gefjun Disturber.

I love that wizards finally caught up with you and printed Foretell! I honestly thought that although Predict was great, it was too specific to turn up in black border, but apparently not!

Yes, I was startled and delighted to see how close foretell was to prepare! The only difference is that prepare automatically gives you the ability to cast it with flash, which was key to the flavour and has certainly affected the way I've designed it.

Wizards have done a bit more interacting with foretell in Kaldheim than I've done with prepare in this set, with things like "second spell of the turn" triggers and "cast from somewhere other than your hand" triggers. But they kinda needed to do that because otherwise foretell doesn't do very much, where gaining the ability to cast at instant speed makes prepare more inherently useful on most of my designs.

Yeah, the differences are very interesting too.

I remember discussing how it needed some upside, and flash makes a lot more sense for Code Geass (where the flavour is very much "surprise! you never guessed", and where it's not an in-world effect it makes sense for a lot of other cards to key off) and support cards make more sense for Kaldheim (where the flavour is more "inevitability" and lots of people in the world care about it). But they end up with quite a different feel despite working almost the same.