There are two kinds of Magic games: casual games for fun, and competitive tournament games. The first kind is what we all start out playing. As we grow more aware of the game on all its levels, some of us try to move into tournament games. This can be a very tricky transition. It's been said that you can never go back. Well, I'm here to help.

First things first, I want to thank you for taking the time to look this over. Any help you can give would be appreciated. I’ve been playing MtG for about nine years now off and on, but I just recently decided to play a tournament. I want his deck to be a contender if possible. Please build for any format that this deck could play in and have a chance of winning. Quick note. I already plan on adding more glimpse’s and more royal assassin’s, so unless you think they don’t belong, I will add more as I get my hands on them. Here’s the deck:

Lands
Swamp x11
Island x9

Spells
Lobotomy x2
Recoil x4
Dark Ritual x4
Bribery x1
Glimpse the Unthinkable x1

Enchantments
Copy Enchantment x3
Followed Footsteps x2
Fear x2
Treachery x1
Persuasionx2

Creatures
Szadek, Lord of Secrets x1
Circu, Dimir Lobotomist x3
Dimir Cutpurse x2
Mindleech Mass x2
Silver Myr x4
Aetherplasm x2
Vedalken Entrancer x3
Royal Assassin x1

Artifacts
Urza’s Filter x2

The deck is not as slow as it used to be, but I know that it lacks the speed necessary to be competitive. My problem is that I don’t want to abandon the theme of milling/creature stealing, which is why I have all of those enchantments. However, any suggestions will be taken to heart. Again, thanks for your time.

Jon Riley

I'll do everything I can, of course. Now, my first impulse was to try and make it Standard legal, but that would mean taking out Lobotomy and Recoil. Since those are some of the best black/blue cards in the game, I'll make it Extended legal instead. So the first step is to take out all the cards that aren't Extended legal. That means Dark Ritual and Treachery. Nothing too essential, thankfully.

Now, as far as being competitive goes, the first task is to speed up the deck. One way to do that it to lower the mana curve, which means taking out Mindleech Mass. I know it's a fun card, but is better left to casual formats. Another way is to add more mana fixing and acceleration. Black and Blue generally aren't good at that, but replacing Silver Myr with Dimir Signet will help. The Signets have the advantage of being able to tap for mana as soon as you play them, and providing both colors of mana so you're not stuck with Islands on the table and Black cards in hand. The third way is to add more card drawing. Dimir Cutpurse is nice, but as a 2/2 with no evasive abilities, it has "block me" written all over it. I advise replacing it with its great-uncle Shadowmage Infiltrator. It has a higher toughness, making it harder to kill, and Fear, making it harder to block.

Speaking of Fear, the card Fear isn't exactly tournament worthy either. If you really want to give a creature Fear, Fear the card is strictly worse than Dragon Shadow. Of course, I think by switching the Cutpurse with the Infiltrator, I may have eliminated your need for Fear at all. In which case, you can probably just use those slots for the extra Glimpses and Assassins you mentioned. But I'd like to suggest something completely different, just for you to think about. This card is a bit out there, and it's not exactly something you'd find in a tournament report, but it does fit your deck beautifully: it's Never-ending Torment. Granted it comes with risks, but you do want a milling deck, and removing specific cards in your opponent's library is better than randomly dumping them in his graveyard, especially with Psychatog so relevant in Extended.
Speaking of Psychatog, this will probably be the only Black/Blue deck in extended not using Psychatog. I'm really holding back here by not including him. Luckily, you've already got ways to stop Dr. Teeth-- Lobotomy and Recoil. Let Psychatog attack. Let the opponent discard his or her whole hand to the thing, ideally. Then Recoil it, sending it back to its master's hand, and hopefully the grave. Better yet, Lobotomize it out of existence. Neverending Torment would provide another way of ridding you of it for good. Technically Circu can get rid of it too, but he's unreliable. You don't need three copies of him. Two'll be enough. If you need any more slots for the cards I recommended, I think the next card on this list to go would be Aetherplasm.
And finally, your lands.

For a Black/Blue deck, a tournament contender should probably have four Watery Grave. Four Underground River too. They're not cheap, not by a long shot, but the more copies you can get, the better. They're expensive for a reason- they're very good. I don't recommend these rare lands to most customers simply because many are on a budget and can't afford to spend $20 on a single card. I don't blame them, neither can I. But if you can get them, do so. Otherwise you can try Dimir Aquaduct for a budget alternative. And in any U/B mill deck, a copy or two of Duskmantle, House of Shadow is appropriate.

That's everything I can do, Jon. It's in your capable hands now.
~BMoor