The Yugi vs. Kaiba Format is the first competitive TCG format there ever was. It includes only the Legend of Blue-Eyes White Dragon booster set and the 2 Original Starter Decks (Yugi & Kaiba). This is Yu-Gi-Oh! in its simplest form. Surprisingly, it is actually difficult and takes a lot more skill than you would think.
Games are almost always very close. The format revolves around battle and monster removal. Let's start with the Four Power Spells, since they are clearly the most powerful cards by far.
RAIGEKI and DARK HOLE are a constant threat and probably the best ways to gain card advantage. This means it is really only safe to summon and attack with 1 monster at a time while these cards are still left in your opponent's deck. This can make getting around high-DEF monsters such as Wall of Illusion and Giant Soldier of Stone very slow, because you usually have to attack them to flip them face-up and then play a Fissure on them the following turn. My favorite way to use these cards is to bait my opponent into summoning multiple monsters by setting my own flip effect monsters or defensive walls in response to their aggression. Another play that sometimes works is to hold Dark Hole or Raigeki when it seems obvious that I should use it (in the face of 2 monsters) and goad my opponent into bringing out a third monster. However, I like to hold one or the other for most of the duel. So I will try to gain advantage with the first copy I see and then hold the other one back to keep my opponent's summons in check. Ideally it is better to hold Raigeki if you can, because it can also be used like a Nobleman of Crossout to clear facedown monsters to swing for game or big damage.
MONSTER REBORN is almost unstoppable since it circumvents Trap Hole. It's one and only weakness is Waboku. The best card to target is obviously Summoned Skull, and it is obviously best to wait until late game to do this. This is the only mainstream card that can special summon a monster (besides Last Will, which is weakened by the Old Ruling and a lack of solid targets). If you want to swarm the field, this is the one card that can do it.
CHANGE OF HEART is a menace. Absolutely devastating to use it on your opponent's Flip Effect monster or when you only need to get one more attack in to kill your opponent. For this reason alone, it is the fourth power spell and is best to hold until late game.
POT OF GREED as good as we all know it to be, is at its weakest form in the Yugi Kaiba Format. I don't even consider it a power spell. Why is that? Because there are so few power cards you can draw off of it. That said, it is a staple and should be played whenever you don't have a trap card or a viable monster play in hand. However, keep in mind there are no cards around that will discard it from your hand, except Card Destruction, which is not a good card. This means there is very little downside to holding it, and it can actually effect how your opponent assesses the game state and the plays that they make.
SUMMONED SKULL is powerful in the end game, but risky to bring out earlier. That is why I like to run 1, it's kind of like a really weak BLS. The only effective way to bring it out is a hard tribute. It is also very powerful to use Change of Heart + Summoned Skull late game. However, you typically don't want to bring it out too early because there is so much generic 1-1 removal and there is the threat of your opponent's Monster Reborn and Change of Heart. Playing Monster Reborn into Summoned Skull can only be stopped by a Waboku, since the special summon avoids Trap Hole and Skull can attack over literally any monster. I find that 2 Summoned Skulls will clog in your hand quite often, which to me was a bit surprising and against my initial intuitions, but having played a lot of this format, it now makes perfect sense. A tribute summon is a bit of an over-extension, and you will wind up holding your Skull for many turns more often than not, even when you have prime tribute fodder like a flipped Man-Eater Bug or Trap Master.
LA JINN, BATTLE OX, and NEO are the primary aggressors. You need them. All 9 of them in my opinion. Think about the math here, there are 9 1-for-1 removal cards (Bug, Fissure, Trap Hole) and 9 Lv4 beaters. Odds are your opponent will have 1-for-1 removal every time you summon one. Just be wary of Trap Holes when you need to get an attack over an opposing monster. And try to summon only one at a time while Raigeki and Dark Hole are still around. They are the best play when your opponent has no monsters, because they demand a response. The easiest way to win in this format is 5 clean attacks coming from one of these guys.
MAN-EATER BUG is a staple at 3. It is an incredibly versatile removal card. However, it is also the slowest form of removal, since it takes 1 turn of commitment to the board, and it is quite vulnerable to Raigeki, Dark Hole, Change of Heart, and even Swords of Revealing Light. Be careful how you use this card and be aware of its weaknesses.
WALL OF ILLUSION and GIANT SOLDIER OF STONE are excellent walls. I like to use only 2 of each, because you don't often want to use them, but when you need to set them to stave off attacks late game, they are amazing. You would think Wall of Illusion is infinitely better, but I like the versatility of using both at 2, because sometimes it actually is better to have Stone. Keep in mind, Wall can be abused by your opponent's man-eater bug or trap master, since they can flip summon, eat 1300-1400 damage, and then re-use the flip effect by re-setting them. Neither of these cards is a particularly good opening play. It is somewhat debatable whether Stone or Mystical Elf is better, since Elf can slide under Trap Hole if you want to go for game.
FISSURE is also a staple at 3. It is particularly useful against Giant Soldier of Stone and Wall of Illusion, which can otherwise be a real pain to get rid of. It can also be used against beaters when necessary. Just remember, it's usually best to use a Fissure in Main Phase 1, not Main Phase 2, because your opponent can just set another monster before you get a chance to swing directly.
TRAP HOLE is the best tempo controller in the format, since it is the only card that can effectively deal with threats coming from the opponent on their turn in 90% of cases. You get 3 of them, and trust me, you will need all 3 to survive long enough in this format. It is a serious threat when one player has a Lv 4 beater and the other has a blank monster zone. It is very difficult to be aggressive with the threat of Trap Hole to impede your progress.
WABOKU is one of the most important cards in the format, and you almost always want to save it until you cannot afford to take any more damage or it is ideal to save your monster (say a La Jinn from a kamikaze with your opponent's La Jinn, in which case only theirs will die if you play Waboku). Be careful though, because going down to 500 or 1000 life points is quite risky due to Reinforcements (which can be activated in the Damage Step) and Just Desserts. Once your opponent has 3 Wabokus in the graveyard, it is safe to go for game with cards like Change of Heart and Monster Reborn to mount a big swing. It plays a similar role to Scapegoat before it came out in the TCG, a 3 of card that let's you live in response to an over-extension and ideally come back with a swift counter attack on your turn when you can play your power spells.
TRAP MASTER is a bit of a crap-shoot, but it is the only way you can remove Trap Holes and Wabokus. It is particularly nice to hit a Waboku on your opponent's turn. My best advice for choosing a target with Trap Master is to pay attention to what cards "could" be traps, depending on whether they were on the field when your opponent wished they had a Trap Hole to respond (for instance, if the S/T was set and you summoned your La Jinn to attack over a Battle Ox, they almost certainly would have played a Trap Hole if the S/T was a Trap Hole). Conversely, if they set a new S/T after that play, there is a decent chance that new S/T is a Trap Hole. It's often nice to have the option to set a Trap Master instead of summoning a beater or setting a defensive wall, especially early game when your opponent is likely playing cautiously with their summons and there is a higher chance that set S/T are real and not bluffs.
DE-SPELL is used strictly to counter SWORDS OF REVEALING LIGHT, which is at 2 in this format. It can be devastating to De-Spell a Swords, and that's why I've gone with the choice of only maining 1 Swords and 1 De-Spell. To me, Swords is a bit of a desperation play that is by no means guaranteed to protect you due to De-Spell. And running 1 Swords is a bit of a mental-counter to people who may be inclined to run 2 De-Spells. However, Swords can also be used aggressively, and that's why I like it enough to continue to main it. It is a powerful move if you hit a Man-Eater Bug while you have no monsters or you can flip up a defense wall in order to Fissure it during mp1 and subsequently attack with a beater.
REINFORCEMENTS is a nifty card, but it can be a bit situational. Either running 1 or 2 is the best number. It works great when you need to power over a beater or protect your own from getting run over. Remember it's almost always better to activate in the damage step when Waboku cannot be chained in response. Also be wary of your opponent's Reinforcements in response to your own.
JUST DESSERTS is a personal tech choice that could easily be filled in by either more monsters or another copy of Swords and/or De-Spell. I find it useful in clinching games and stealing games I probably shouldn't have won. It's also nice that it is chainable to Trap Master. It's best when games are wars of attrition and neither player can seem to capitalize with any of their power cards or when you had to use both your copies of Raigeki and Dark Hole to stay in the game. 2 Just Desserts can easily be 3000 damage if your opponent is trying to kill you with Monster Reborn and Change of Heart or just a big swarm. This is a huge amount of damage and an additional threat your opponent has to consider when debating whether or not to use their Wabokus. There is also almost no way to eliminate the possibility of Just Desserts with the lack of S/T removal or a Jinzo in this format.
Other decks: DRAGONS
Games are almost always very close. The format revolves around battle and monster removal. Let's start with the Four Power Spells, since they are clearly the most powerful cards by far.
RAIGEKI and DARK HOLE are a constant threat and probably the best ways to gain card advantage. This means it is really only safe to summon and attack with 1 monster at a time while these cards are still left in your opponent's deck. This can make getting around high-DEF monsters such as Wall of Illusion and Giant Soldier of Stone very slow, because you usually have to attack them to flip them face-up and then play a Fissure on them the following turn. My favorite way to use these cards is to bait my opponent into summoning multiple monsters by setting my own flip effect monsters or defensive walls in response to their aggression. Another play that sometimes works is to hold Dark Hole or Raigeki when it seems obvious that I should use it (in the face of 2 monsters) and goad my opponent into bringing out a third monster. However, I like to hold one or the other for most of the duel. So I will try to gain advantage with the first copy I see and then hold the other one back to keep my opponent's summons in check. Ideally it is better to hold Raigeki if you can, because it can also be used like a Nobleman of Crossout to clear facedown monsters to swing for game or big damage.
MONSTER REBORN is almost unstoppable since it circumvents Trap Hole. It's one and only weakness is Waboku. The best card to target is obviously Summoned Skull, and it is obviously best to wait until late game to do this. This is the only mainstream card that can special summon a monster (besides Last Will, which is weakened by the Old Ruling and a lack of solid targets). If you want to swarm the field, this is the one card that can do it.
CHANGE OF HEART is a menace. Absolutely devastating to use it on your opponent's Flip Effect monster or when you only need to get one more attack in to kill your opponent. For this reason alone, it is the fourth power spell and is best to hold until late game.
POT OF GREED as good as we all know it to be, is at its weakest form in the Yugi Kaiba Format. I don't even consider it a power spell. Why is that? Because there are so few power cards you can draw off of it. That said, it is a staple and should be played whenever you don't have a trap card or a viable monster play in hand. However, keep in mind there are no cards around that will discard it from your hand, except Card Destruction, which is not a good card. This means there is very little downside to holding it, and it can actually effect how your opponent assesses the game state and the plays that they make.
SUMMONED SKULL is powerful in the end game, but risky to bring out earlier. That is why I like to run 1, it's kind of like a really weak BLS. The only effective way to bring it out is a hard tribute. It is also very powerful to use Change of Heart + Summoned Skull late game. However, you typically don't want to bring it out too early because there is so much generic 1-1 removal and there is the threat of your opponent's Monster Reborn and Change of Heart. Playing Monster Reborn into Summoned Skull can only be stopped by a Waboku, since the special summon avoids Trap Hole and Skull can attack over literally any monster. I find that 2 Summoned Skulls will clog in your hand quite often, which to me was a bit surprising and against my initial intuitions, but having played a lot of this format, it now makes perfect sense. A tribute summon is a bit of an over-extension, and you will wind up holding your Skull for many turns more often than not, even when you have prime tribute fodder like a flipped Man-Eater Bug or Trap Master.
LA JINN, BATTLE OX, and NEO are the primary aggressors. You need them. All 9 of them in my opinion. Think about the math here, there are 9 1-for-1 removal cards (Bug, Fissure, Trap Hole) and 9 Lv4 beaters. Odds are your opponent will have 1-for-1 removal every time you summon one. Just be wary of Trap Holes when you need to get an attack over an opposing monster. And try to summon only one at a time while Raigeki and Dark Hole are still around. They are the best play when your opponent has no monsters, because they demand a response. The easiest way to win in this format is 5 clean attacks coming from one of these guys.
MAN-EATER BUG is a staple at 3. It is an incredibly versatile removal card. However, it is also the slowest form of removal, since it takes 1 turn of commitment to the board, and it is quite vulnerable to Raigeki, Dark Hole, Change of Heart, and even Swords of Revealing Light. Be careful how you use this card and be aware of its weaknesses.
WALL OF ILLUSION and GIANT SOLDIER OF STONE are excellent walls. I like to use only 2 of each, because you don't often want to use them, but when you need to set them to stave off attacks late game, they are amazing. You would think Wall of Illusion is infinitely better, but I like the versatility of using both at 2, because sometimes it actually is better to have Stone. Keep in mind, Wall can be abused by your opponent's man-eater bug or trap master, since they can flip summon, eat 1300-1400 damage, and then re-use the flip effect by re-setting them. Neither of these cards is a particularly good opening play. It is somewhat debatable whether Stone or Mystical Elf is better, since Elf can slide under Trap Hole if you want to go for game.
FISSURE is also a staple at 3. It is particularly useful against Giant Soldier of Stone and Wall of Illusion, which can otherwise be a real pain to get rid of. It can also be used against beaters when necessary. Just remember, it's usually best to use a Fissure in Main Phase 1, not Main Phase 2, because your opponent can just set another monster before you get a chance to swing directly.
TRAP HOLE is the best tempo controller in the format, since it is the only card that can effectively deal with threats coming from the opponent on their turn in 90% of cases. You get 3 of them, and trust me, you will need all 3 to survive long enough in this format. It is a serious threat when one player has a Lv 4 beater and the other has a blank monster zone. It is very difficult to be aggressive with the threat of Trap Hole to impede your progress.
WABOKU is one of the most important cards in the format, and you almost always want to save it until you cannot afford to take any more damage or it is ideal to save your monster (say a La Jinn from a kamikaze with your opponent's La Jinn, in which case only theirs will die if you play Waboku). Be careful though, because going down to 500 or 1000 life points is quite risky due to Reinforcements (which can be activated in the Damage Step) and Just Desserts. Once your opponent has 3 Wabokus in the graveyard, it is safe to go for game with cards like Change of Heart and Monster Reborn to mount a big swing. It plays a similar role to Scapegoat before it came out in the TCG, a 3 of card that let's you live in response to an over-extension and ideally come back with a swift counter attack on your turn when you can play your power spells.
TRAP MASTER is a bit of a crap-shoot, but it is the only way you can remove Trap Holes and Wabokus. It is particularly nice to hit a Waboku on your opponent's turn. My best advice for choosing a target with Trap Master is to pay attention to what cards "could" be traps, depending on whether they were on the field when your opponent wished they had a Trap Hole to respond (for instance, if the S/T was set and you summoned your La Jinn to attack over a Battle Ox, they almost certainly would have played a Trap Hole if the S/T was a Trap Hole). Conversely, if they set a new S/T after that play, there is a decent chance that new S/T is a Trap Hole. It's often nice to have the option to set a Trap Master instead of summoning a beater or setting a defensive wall, especially early game when your opponent is likely playing cautiously with their summons and there is a higher chance that set S/T are real and not bluffs.
DE-SPELL is used strictly to counter SWORDS OF REVEALING LIGHT, which is at 2 in this format. It can be devastating to De-Spell a Swords, and that's why I've gone with the choice of only maining 1 Swords and 1 De-Spell. To me, Swords is a bit of a desperation play that is by no means guaranteed to protect you due to De-Spell. And running 1 Swords is a bit of a mental-counter to people who may be inclined to run 2 De-Spells. However, Swords can also be used aggressively, and that's why I like it enough to continue to main it. It is a powerful move if you hit a Man-Eater Bug while you have no monsters or you can flip up a defense wall in order to Fissure it during mp1 and subsequently attack with a beater.
REINFORCEMENTS is a nifty card, but it can be a bit situational. Either running 1 or 2 is the best number. It works great when you need to power over a beater or protect your own from getting run over. Remember it's almost always better to activate in the damage step when Waboku cannot be chained in response. Also be wary of your opponent's Reinforcements in response to your own.
JUST DESSERTS is a personal tech choice that could easily be filled in by either more monsters or another copy of Swords and/or De-Spell. I find it useful in clinching games and stealing games I probably shouldn't have won. It's also nice that it is chainable to Trap Master. It's best when games are wars of attrition and neither player can seem to capitalize with any of their power cards or when you had to use both your copies of Raigeki and Dark Hole to stay in the game. 2 Just Desserts can easily be 3000 damage if your opponent is trying to kill you with Monster Reborn and Change of Heart or just a big swarm. This is a huge amount of damage and an additional threat your opponent has to consider when debating whether or not to use their Wabokus. There is also almost no way to eliminate the possibility of Just Desserts with the lack of S/T removal or a Jinzo in this format.
Other decks: DRAGONS
The Dragons deck revolves around Lord of D. and the Flute of Summoning Dragon combo to bring out Blue-Eyes White Dragons and Tri-Horned Dragons. This is difficult to pull off quickly, and seriously complicated by the fact that all decks play 3 Wabokus, Dark Hole, and Raigeki. A potential way to deal with this is to use Trap Masters. It is further hindered by the fact that the Old Ruling on Last Will requires one to activate it BEFORE your monster is sent to the Graveyard, making it harder to summon Lord of D. It would be much more powerful if you could summon a beater, bait out a Trap Hole, play Last Will into Lord of D. and bring out your Dragons, but alas this combo did not work back in the 2002 rules of the TCG.
Other decks: STALL MILL
I was thinking about how 2 Card Destruction could be abused in this format, and this is the best idea I can come up with. Since most normal games in this format take about 10+ turns, all you would have to do in theory would be to stall the game out a little bit longer to 20 turns, so your opponent has exactly 12 cards left in deck and 6 cards in hand, then activate 2 Card Destruction on your turn. Ideally you only need to make sure you don't deck yourself out, and you can manipulate the number of cards in your hand by setting spells, traps, and monsters to draw the maximum number without killing yourself. You could also do this to ensure or increase the odds that you draw your second Card Destruction off of your first Card Destruction if you only have drawn 1 that game.
Other decks: STALL BURN?
This deck revolves around Just Desserts, Ookazi (Normal Spell, 800 dmg), and potentially Hinotama (Normal Spell, 500 dmg). In theory, it could run a handful of beaters, 3 Stone Soldiers, 3 Elfs, 3 Bugs, 2 Swords, 3 Waboku, etc. It would only require ~2 attacks by one of your beaters early on, and then you can go into stall mode, setting lots of spells and holding off your opponent with walls. Then, when you have enough damage to kill your opponent or get them really really low, you can fire off all of your burn at once. This would work best in response to a full board of your opponent's monsters to maximize Just Desserts.
Other decks: STALL EXODIA?
Probably wouldn't work very well, with no viable methods to search out or retrieve Exodia pieces from the graveyard, meaning Card Destruction would probably fail in this build. Yeah, I don't see this deck being any good, but maybe someone can crack a decent build. Your opponent could also side in Card Destruction and that would basically kill your gameplan.
I was thinking about how 2 Card Destruction could be abused in this format, and this is the best idea I can come up with. Since most normal games in this format take about 10+ turns, all you would have to do in theory would be to stall the game out a little bit longer to 20 turns, so your opponent has exactly 12 cards left in deck and 6 cards in hand, then activate 2 Card Destruction on your turn. Ideally you only need to make sure you don't deck yourself out, and you can manipulate the number of cards in your hand by setting spells, traps, and monsters to draw the maximum number without killing yourself. You could also do this to ensure or increase the odds that you draw your second Card Destruction off of your first Card Destruction if you only have drawn 1 that game.
Other decks: STALL BURN?
This deck revolves around Just Desserts, Ookazi (Normal Spell, 800 dmg), and potentially Hinotama (Normal Spell, 500 dmg). In theory, it could run a handful of beaters, 3 Stone Soldiers, 3 Elfs, 3 Bugs, 2 Swords, 3 Waboku, etc. It would only require ~2 attacks by one of your beaters early on, and then you can go into stall mode, setting lots of spells and holding off your opponent with walls. Then, when you have enough damage to kill your opponent or get them really really low, you can fire off all of your burn at once. This would work best in response to a full board of your opponent's monsters to maximize Just Desserts.
Other decks: STALL EXODIA?
Probably wouldn't work very well, with no viable methods to search out or retrieve Exodia pieces from the graveyard, meaning Card Destruction would probably fail in this build. Yeah, I don't see this deck being any good, but maybe someone can crack a decent build. Your opponent could also side in Card Destruction and that would basically kill your gameplan.
