Greetings, I, the one and only Magical Slime of Time greet you. I come to talk about advice on how to work on building a deck, playing the game, and various cards that are useful that are not in the mainstream (although I will list those too for effect)

I. Ok, the first thought on deck construction in any game, pick a theme for your deck, preferably a theme currently that doesn't base itsself on a specific card but that's ok (but annoying, for you want to base a deck off of at least 2 different cards that can pull the combo idea) Example being if your going dragon deck, lord of dragons/flute and the kaiser seahorse (not out yet) to get out the blue eyes white dragon.

II. So you picked a deck theme (stompy (f/s), dragon, exodia, direct damage, etcetra. The next thing is to pick out the cards that will be necessary for your theme, and work from there, incorperating the power cards that you will NEED to continue it. Usually it is a bad idea to play with cards that force it on luck, because they are usually clutch cards (cards you have nothing to lose) So if it has an effect, think to yourself, If i lose with this effect the first time i use it, will i still come out ahead, if no other cards are used for modify. (or, if I can only use this effect once before the card is destroyed, was it worth it?)

III. Once you have the main cards for your theme, examine your deck for weaknesses and work on lowering them, for example, most stompy decks have a weakness that they can't really handle too much magickal removal, and usually stalemate vs another stompy, etc.. Thusly, get cards that can balance those weaknesses.

IV. On choosing monster cards - If a monster is a non tribute/non effect, it should be 1800/xxxx or xxxx/1800 as minimum stats for a tourney level deck. Also examine all the monsters that have abilities, which can either make or break them for your deck design. A few prime examples of deck specific monsters are the Witch's apprentice, Jizno #7, Catapult Turtle, and the Bistro Butcher

A. Tribute monsters - Tribute monsters are the most powerful in the game, but they come with a steep cost, of killing your own monster. With that in mind, you want to make your deck with only a few, due to the cost, and the chance of being getting burned when your hand is only filled with tribute monsters.

B. Spec. Requirement monsters - Specific requirement monsters, like Harpie Lady Sisters require a bit more planning, you need to design your deck in a way to balance the cards needed so you can play the unique card that can't be summoned normally, while also remembering that it can be countered. Like if your deck was designed for harpie sisters, you'd want 3 harpies in your deck, and make sure you can have one anytime you drew the elegent egotist.

C Fusion monsters - Fusion monsters, although some of the most powerful are some of the most frustrating. (take a look at the cards required and you'll see what i mean) It is only really worth playing fusion if you are experienced, and the cards can fit in your deck without weakening it too much, cause yes, that Skull Knight is powerful, but till you can get all the things to get it out, your stuck with 2 subpar monsters. There are 2 fusions I currently reccommend, Black skull dragon (because the monsters are powerful anyway, well at least one is) and the Twin Headed Thunder dragon. (because of it's ability, it speeds up the chances of you being able to play it) Cards that allow you to subfusion would be necessary for a fusion deck if you can get them.

V. On choosing Magic/Trap cards - The thought is simple, will this card stop them from doing what they want to do, or help me do what I want to do. On cards that effect the opponent, you want to put in cards that will work, reguardless of what the deck is. The deck is your source of power, and if you are cut off from it, you lose, so be careful about cardbounce to your library. Also remember, the average life expectency of a monster is usually 3 turns.

VI. Focus vs spread, the power of cards - Almost all the time, if you are using a card, more is better, and the more focused it is, the better (although a bit more risky) it will be. A perfect example would be take the field card yami, and the equipment card, Demon axe. At full power, both give the same damage boost, 1000, but yami spreads it through 5 monsters, and Demon axe is directed at one, which ultimately can break through barriers easier.

VII. So you got a deck, trim it down and balance - Ok, you probably got a whole bunch of cards for your idea of a deck, now go through the cards, and pick out the best of the cards, and try to have it so your deck has just a few more monsters than magic/traps. Monsters are the main thing that guard your life, not the flashy one cast spells, even though sometimes more powerful. You also want to have your deck as between 40-50 cards, so you can guarantee you will get the cards you need.

VIII. Tweak! - Now that you got a deck, try running through it a few times, like solitare, and examine how it runs. Usually, a good deck can hold it's own reguardless of going first or second, which usually is the difference between the agressor and defender in the first few turns. If you find that your deck is lacking in a way, trade in cards from the ones you were going to use, vs the ones in your deck, to try to improve it.

IX. Duel - Nothing can show you more on how to fix your deck by going through a couple dozen good duels, so find opponents and duel them, if your deck holds up, you wanna go against other people, find someone that can crack your deck open so you can find it's weaknesses.