How to Be Good at Yu Gi Oh!

Learn how to play Yu-Gi-Oh. Familiarize yourself with the rules, as well as different card interactions and mechanics. Yu-Gi-Oh! is a complicated game, so it is recommended that you keep the rulebook and wiki handy while playing, get advice from a more experienced player, and/or use a fully automatic online simulator like YGOPro or DevPro while you are learning.

• Also have a good understanding of the more complex mechanics such as chaining, targeting, missing the timing, and different conjunctions.

Build a good deck. Focus on one central archetype or theme in your deck, not a random collection of cards that don't work together. An archetype is a group of cards who share a common word or phrase in their name, whose effects support other cards of that archetype. Make sure your cards don't clash with each other, and take out cards that are useless in most situations. If you don't know what to build, you can look online for popular decks or even copy someone else's deck to get the hang of playing and deck-building.

• Have a good balance of monsters, spells, and traps. A good ratio is 15-20 monsters, 10-15 spells, and 5-10 traps, but you don't have to follow this exactly.
• Use effect monsters unless your deck focuses on normal monsters, since effect monsters are generally more useful. Get ones with good effects and stats, and don't use too many high-level ones or ones you can't summon easily. Have spells that destroy monsters, help you summon or search stuff, destroy spells and traps, and protect your monsters. Use traps that prevent summons, destroy stuff, negate stuff, and prevent attacks.
• Keep your deck at 40 cards, or as close to 40 as possible. Keeping you deck close to the lower limit will help you draw the cards you need to win. If decking out is a serious problem for your deck, you could increase it to 41 or 42.

Build an Extra Deck. The Extra Deck contains Fusion, Synchro, and Xyz monsters which you can summon using their own summoning mechanics. Since the monsters in the Extra Deck are so accessible and have useful effects, it can be a good way to save yourself or push for a win. There is a limit of 15 cards in the Extra Deck, so fit in as many as you can.

• Xyz monsters are the most summonable cards in the Extra Deck. Since they only require two monsters of the same level, nearly all decks can bring them out. If your deck has three or more easily summoned monsters of the same level, you should include at least a few Xyz monsters of that Rank.
• Synchro monsters will require a Tuner. Add the levels of your tuner(s) to your most commonly summoned monsters, and include some Synchro monsters of that level. Make sure you can fulfill any specific summoning requirements of the Synchro monsters, and that their effects will help your deck.
• Fusion monsters are more specialized. Only use them if your deck is designed around Fusion. Use the ones with good effects and materials that are not overly specific.

Test your deck. Find someone to duel against to see how well your deck runs. If a card just seems to be clogging up your deck, take it out. If your deck has a glaring weakness to something, shore it up with spell/trap cards. If you don't know what to use, you can check online for other people's builds to get more ideas or post in a forum for critique.

Understand card advantage. Advantage is described in terms of pluses and minuses. For example, if you have 4 cards in your hand and play Pot of Greed, you will end up with 5 cards in your hand. Therefore, Pot of Greed is a +1 to hand advantage. Don't play cards that will use up a lot of your resources to accomplish very little. Instead, play cards that will increase your advantage. Also, be wary of cards that let your opponent draw or force you to skip drawing. These cards can be good if you are pushing for a win, but don't use them when it would help your opponent more than you.

• Spells and Traps that make you discard cards are usually very powerful, but could be bad in a deck that can't maintain a large hand. On the other hand, paying life points or giving them to your opponent seems like a bad deal, but paying some LP is better than losing, and a few powerful attacks can easily take back any LP they've gained.

Know the current metagame. In any given Yu-Gi-Oh! format, there will be a couple of decks which stand above the others in terms of consistency or power. Get to know these decks and their playstyles, so you will know how to play when facing one of these decks.

Understand card effects. Make sure to read all cards in your deck and all cards an opponent plays carefully, and have a good knowledge of what the text means. Read the full effect; don't just skim it. Be familiar with terms like "Excavate", "detach", "destroy", etc. If you use a card that you don't fully understand, look up rulings on it.