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Foreword: Like the English language, I'm sure all rules to game and card design have exceptions. These are mostly guidelines of design, not laws. If you disagree with any particular statement, feel free to say so, but you don't have to go off on a rant about it.
This topic is not about enjoying making cards, it is about making cards to be enjoyed. If you are not interested in design or actually dueling with cards you create, this topic is probably not worth your time.
This topic isn't premeditated, just my own meandering thoughts.
Player-Player Interaction:
Why do you think Soltaire is not played at parties? If you have four people sitting around a table with four decks of playing cards, it's unusual that they decide to play Soltaire. Generally, when you're with another person and playing games, it's more enjoyable to play a game where you're interacting with them. This also means that it's generally not as fun in Yugioh to play a game where the opponent's actions don't influence you at all.
Exodia is an example of breaking this game design guideline in the extreme. When playing an Exodia Deck (based around drawing, not stalling) you might as well be playing with yourself - very rarely does your opponent interact with your Deck at all. It's just "who gets out a win first" rather than "who gets out a win WHILE PREVENTING an opponent's win". This is also generally the reason OTKs and FTKs are bad for the game - they're one-player things. Chances are that most players wouldn't say a game was 'bad' if it ended on the first turn, but they were somehow able to play half their Deck through various card effects and there was plenty of back-and-forth.
Lame Ducks:
A Lame Duck is a game design term that means a game can reach a point where only one player is at all likely to win (90%+ sorta chance) but the game can still go on for a while. In Yugioh, this can very easily happen. If you draw a terrible hand, and your opponent draws a great hand, then the entire duel might be completely pointless since both players could tell the outcome before any cards hit the field. Lame Ducks are, at the risk of redundancy, lame. No-one likes playing Lame Duck games as the loser, and often it's not even very fun as the winner, since you don't get any Player-Player Interaction - the opponent just can't do anything. To avoid Lame Ducks ruining the game or format, avoid inconsistent cards that can give dead hands, and avoid lockdowns that make playing pointless.
Slippery Slope:
Slippery Slope is a term in game design which means that when one player gains an advantage, it becomes easier to gain more advantage. An extreme of this in Yugioh would be that every time you destroy an opponent's card or deal damage to their Life Points, you draw a card and gain 1000 Life Points. That means that the first player to get a head start very quickly can put their opponent in a situation without as many options and where fighting back is very difficult. Generally, a Slippery Slope is a bad thing since it can very easily lead to a Lame Duck. To minimise Slippery Slope, try not to have cards that require you to be winning for them to work, that work much better if you're winning, or that punish a player with few cards/LPs.
On the other slide, be careful about removing Slippery Slope all together. Sid Meier is oft-quoted as saying 'A game is a series of interesting decisions'. While this might not apply to all games, I feel it very much does apply to Yugioh. If you reset the entire game except LP, like Fiber Jar had been flipped, every time a direct attack was made (to stop a player 'taking control' of the match) then the game would just be a disconnected series of mini-events and wouldn't feel like a single duel. Generally, the fact a losing player in Yugioh generally has less cards to fight back with is more than enough of a Slippery Slope to avoid this, but it's worth saying.
Starting Conditions:
My favourite writer on game design and one of my favourite game developers, Sirlin (whose articles you should read if you find this interesting), spends a lot of time during development making sure that all his game's match-ups are fair, and often stresses the importance of in-match and out-of-match decisions. The rule here is that when you start a match in a fighting game, both players should have as close to a 50% win chance (if equal skill) as possible.
It's important to note how this does and does not translate to Yugioh. In Yugioh, I believe there might as well be more theoretically constructable Decks than there are atoms in the universe. I am not proposing that you balance all of those against every other one. People should be able to make losing Decks. Where this does apply is when two good Decks are matched up with each other. This means that if both players are equally good and have equally good Decks, a match shouldn't start as a lame Duck.
That means that Zombies and Macro shouldn't both exist in the same game - zombies are playing a Lame Duck game from turn 1 a lot of the time. That doesn't mean you can't have Graveyard effects and RFG effects in the same game - but no archtype should have every monster RFGing stuff from the opponent's Graveyard in the same format that the Graveyard is useful. In the TCG, Macro vs Zombies isn't much of a problem because Zombies won't face Macro that often and it can often be blown away with MST or something. The time this is a serious problem, though, is anti-cards. Yes, Chimeratech is the worst offender here. If someone has a Cyber Dragon in their Main Deck and Chimeratech Fortress Dragon in their Extra Deck when the game starts, a Machine-using opponent can start at an unfair disadvantage. Avoid anything like this that puts players at too much of a disadvantage from turn 1. It's unaviodable sometimes, but do your best.
Representation:
While writing this, I stumbled upon an article that does this section better than I would.
http://blog.ihobo.co...t-colossus.html
Basically, Cloudians would be a lot less fun to play if their names were "Archtype 12 Monster 1" "Archtype 12 Monster 2" [...ect] and their types were all "Type 4" with "Attribute 2". They would be exactly the same game-design wise, but they wouldn't be as fun because there's simply no visualisation of what they are. In Written Cards, we can easily fall into the trap of having a good, fair, game without any story, image, or anything of the sort. Preceding sets and archtype with a few paragraphs of flavor text, or adding it to the end of a card, can make a world of difference in making a card come alive to the player. It might seem trivial to some people that want nothing but balance, but it makes a world of difference to having an enjoyable set and format.
More to come when thoughts wonder into my head. This is just ideas jotted down, but I doubt I'll ever find time to tidy it up.
EDIT:
This time I'm going to cover some broader concepts and see if they can be applied to design of cards in the current format at all.
Randomness
How random should a game be? To answer that, what does randomness give to a game? Often, it closes a skill gap. Let me illustrate with an example. In a zero-randomness game where everything is known (Chess), a better player wins the vast majority of the time. In the game of coin-flip, "heads I win, tails you win." There is no skill. Does that make randomness an evil thing that makes skill meaningless? Not if it's done right. Which of these games sound most fun:
Personally, I feel #2 sounds most fun. You want a chance, but you want to feel the games mean something and that you improve as you play more. Games are fun when you feel you out-played your opponent, but that the game wasn't pre-decided either. Translating this to Yugioh, drawing is usually random enough to reach #2, so the lesson to take away is not to make things too much more random. Inconsistent Decks, dice/coin based cards with dramatic effects, or total game-changers that can't be consistently searched, all present this risk. They're still passable if they have other good design principles, but do think about if you're making the game into coin-flip.
Options/Card Entropy
Imagine a situation. Two players are in a game, maybe around turn 3, Decks have been made about equally well, it's Player A's turn and we want to judge how skilled Player A is. What differs a skilled player from an unskilled one. Deck Design? - Well, that would make duels rather pointless, we'd just feed them into the latest DS game and let the computer decide. The answer is choices. A skilled player, when having multiple options, picks the right one. In games that aren't turn-based, mechanical aspects might come into it, but in Yugioh, we only have choices. And we like skill to be important! That's what lets you 'out-play' your opponent and lets us avoid playing that stupid game of coin-flip. So, we clearly need to give a player enough options to show their skill. What options can you make in a Yugioh game? Which cards to activate or in which order, which synchros/xyz to make with your materials, what to target with your cards, when to attack and what to attack. That seems like there would usually be plenty of choices, but consider the situation where lots of card removal has been played - you have nothing to activate in the Graveyard and your hand/field has a total of 2 cards, which you can't synchro/xyz with for some reason. How many options do you have that aren't stupid? Probably not many. The vast majority of players would make the same choices, you aren't showing any skill. Now you have a total of ten cards available and there are eight targets on your opponent's side of the field. There's probably at least five almost equally viable ways to play the hand - which one you choose is using your skill. More cards on both sides of the field usually leads to more options and more chances to prove your skill. I'm going to refer to the number of cards usable from the grave/deck, cards in your hand/field, cards in the extra Deck that have a chance to come into play, ect, as 'card entropy' a high card entropy is usually good for the game. But when can it be bad? Unfortunately for Yugioh, OTKs and Exodia mean a high card entropy can destroy player-player interaction and end the duel far too quickly if they aren't designed carefully.
How to use this carefully to better our card design then? Well, always pay attention to if your cards are increasing or decreasing card entropy. 1-4-1 destruction/negation/removal like D-Prison, Solemn, Bottomless, MST, strictly decrease card entropy (by 2 cards generally). Try and avoid things like this. We're designing two archtypes, the Happy Bunnies and their enemies, the Belligerent Badgers. Which of them has the better designed card?
|Rampaging Badgerz|
|Normal Spell|
|Activate only while you control a "Belligerent Badger" monster. Discard 1 card to send 2 cards on the field to the Graveyard.|
|Bunny Funtime|
|Normal Spell|
|Activate only whlie you control a "Happy Bunny" monster. Your opponent draws 1 card. During your End Phase, draw 2 cards.|
The Badgers really pull down the card entropy with that card, a -4 to the options! Bunnies are much nicer on the other hand, one card turns into three! A +2 to the options available, that's a card that promotes some skill! Try and leave removal to your big monsters or situational cards, and if possible, compensate the card entropy somehow, like giving your opponent a draw for each card destroyed. Even a token is better than nothing. Card removal of course, happens, but it doesn't have to be badly designed.
Comebacks
Player A is having a bad game. 3000 LP left, a set card and 2 in his hand to synchro, xyz, three backrows, two hand cards and 6500 Life Points of his opponent. Is the game over? Considering the three backrows can probably negate anything Player A tries to do with the current card pool, yes, the game is over almost every time. Should it be? Hell no! The anime doesn't put the hero behind before he wins in most of his duels out of habit. It's because comebacks are fun - when you can make a comeback, there are less Lame Duck situations. There's always a reason to keep playing. It's the opposite of slippery slope. But how do we encourage comebacks? For one, a high Card Entropy but few 1-4-1 removals are good, especially removal that can ruin a Normal Summon (Solemns, Bottomless) - when you have a high card entropy, you can combine cards in various ways - discard 1 to activate 1 then use the first one's effect from the Graveyard to summon an entirely new one from your hand and combine them to make Super-Awesome Kickass Monster, for example. If you draw Silly Spellcard as the only card on your hand or field, and still Summon Super-Awesome Kickass Monster without activating anything in the Graveyard, then Silly Spellcard is either extremely situational, or possibly overpowered enough that it adds too much luck (who draws it), especially with how hard searching spell cards can be. Generally, think about what situations a card is most likely to trigger in, and where it will have the biggest impact, and if this is good or bad for comebacks. Let's flesh out those archtypes a bit more!
|Badger Dig a Trap Hole|
|Counter Trap|
|Shuffle a "Belligerent Badger" monster in your Graveyard into your Deck to negate the Normal Summon of an opponent's monster and shuffle it into their Deck.|
|Bunny Helps People|
|Trap Card|
|Activate when a "Happy Bunny" monster on your side of the field is destroyed as a result of an opponent's attack. Return that monster and 1 monster your opponent controls to the owner's hand, then add 1 monster from your Graveyard to your hand and end the Battle Phase.|
Well, the Badger's card is going to have the most impact when your opponent needed that monster to hold on for another turn, or to start a combo that would put them back in the game, generally when they have no/few other monsters and no/few other ways to Summon monsters. That really works against comebacks, pretty bad design. I am disappointed, Badgers! Bunnies, on the other hand, are doing a great job again. The card implies that your opponent is confident enough to attack, so is probably not super-far behind, doesn't restrict your opponent's options, has a wide number of targets (any monster in your Graveyard), and generally seems much better design, good job Happy Bunnies!
"Balance" in terms of card design
Balance and design values are not the same thing, and sometimes might stand against each other. Underpowered cards are always bad design - they add more noise you have to learn to filter to make good Decks and increase clutter when searching through cards. Overpowered cards are more complicated. If there are enough overpowered generic cards that all Decks feel too similar, that's bad, but if an overpowered card fits good design principles, like encouraging high card entropy, player-player interaction, and comebacks, then it might be justified. Monster Reborn is a great example of this. It is certainly a very powerful card, but it has a greatest impact when you need a strong monster to hold on and don't have many ways to populate your field. I've seen it included in quite a few comebacks for sure, and it sets off many combos to increase card entropy. Pot of Greed is more debatable. It increases card entropy and is generally most useful when you're a bit behind, but it can simply make a format too fast and there isn't much skill to using it - you usually instantly activate it if you're lucky enough to draw it. If Exodia and other lockdowns and OTKs were removed from the format, I think PoG might quite happily sit on the limited list, albeit not perfectly designed with the luck it adds. A specific Deck (e.g. Cloudians or something) being overpowered, however, can make other Decks feel weak and make competitive players feel like they don't have much choice in Deck design. That's bad. Some overpowered cards can be justified by design, but not too many, and not too Deck-specific..
Outro
Hopefully this helps any of you planning to make cards for dueling purposes design cards which create a fun, skill-based environment for all players. If you have any points you're interested in or want to discuss, please post below! Feel free to disagree with anything above, if no-one points out when I'm wrong, it's much harder to learn.
This topic is not about enjoying making cards, it is about making cards to be enjoyed. If you are not interested in design or actually dueling with cards you create, this topic is probably not worth your time.
This topic isn't premeditated, just my own meandering thoughts.
Player-Player Interaction:
Why do you think Soltaire is not played at parties? If you have four people sitting around a table with four decks of playing cards, it's unusual that they decide to play Soltaire. Generally, when you're with another person and playing games, it's more enjoyable to play a game where you're interacting with them. This also means that it's generally not as fun in Yugioh to play a game where the opponent's actions don't influence you at all.
Exodia is an example of breaking this game design guideline in the extreme. When playing an Exodia Deck (based around drawing, not stalling) you might as well be playing with yourself - very rarely does your opponent interact with your Deck at all. It's just "who gets out a win first" rather than "who gets out a win WHILE PREVENTING an opponent's win". This is also generally the reason OTKs and FTKs are bad for the game - they're one-player things. Chances are that most players wouldn't say a game was 'bad' if it ended on the first turn, but they were somehow able to play half their Deck through various card effects and there was plenty of back-and-forth.
Lame Ducks:
A Lame Duck is a game design term that means a game can reach a point where only one player is at all likely to win (90%+ sorta chance) but the game can still go on for a while. In Yugioh, this can very easily happen. If you draw a terrible hand, and your opponent draws a great hand, then the entire duel might be completely pointless since both players could tell the outcome before any cards hit the field. Lame Ducks are, at the risk of redundancy, lame. No-one likes playing Lame Duck games as the loser, and often it's not even very fun as the winner, since you don't get any Player-Player Interaction - the opponent just can't do anything. To avoid Lame Ducks ruining the game or format, avoid inconsistent cards that can give dead hands, and avoid lockdowns that make playing pointless.
Slippery Slope:
Slippery Slope is a term in game design which means that when one player gains an advantage, it becomes easier to gain more advantage. An extreme of this in Yugioh would be that every time you destroy an opponent's card or deal damage to their Life Points, you draw a card and gain 1000 Life Points. That means that the first player to get a head start very quickly can put their opponent in a situation without as many options and where fighting back is very difficult. Generally, a Slippery Slope is a bad thing since it can very easily lead to a Lame Duck. To minimise Slippery Slope, try not to have cards that require you to be winning for them to work, that work much better if you're winning, or that punish a player with few cards/LPs.
On the other slide, be careful about removing Slippery Slope all together. Sid Meier is oft-quoted as saying 'A game is a series of interesting decisions'. While this might not apply to all games, I feel it very much does apply to Yugioh. If you reset the entire game except LP, like Fiber Jar had been flipped, every time a direct attack was made (to stop a player 'taking control' of the match) then the game would just be a disconnected series of mini-events and wouldn't feel like a single duel. Generally, the fact a losing player in Yugioh generally has less cards to fight back with is more than enough of a Slippery Slope to avoid this, but it's worth saying.
Starting Conditions:
My favourite writer on game design and one of my favourite game developers, Sirlin (whose articles you should read if you find this interesting), spends a lot of time during development making sure that all his game's match-ups are fair, and often stresses the importance of in-match and out-of-match decisions. The rule here is that when you start a match in a fighting game, both players should have as close to a 50% win chance (if equal skill) as possible.
It's important to note how this does and does not translate to Yugioh. In Yugioh, I believe there might as well be more theoretically constructable Decks than there are atoms in the universe. I am not proposing that you balance all of those against every other one. People should be able to make losing Decks. Where this does apply is when two good Decks are matched up with each other. This means that if both players are equally good and have equally good Decks, a match shouldn't start as a lame Duck.
That means that Zombies and Macro shouldn't both exist in the same game - zombies are playing a Lame Duck game from turn 1 a lot of the time. That doesn't mean you can't have Graveyard effects and RFG effects in the same game - but no archtype should have every monster RFGing stuff from the opponent's Graveyard in the same format that the Graveyard is useful. In the TCG, Macro vs Zombies isn't much of a problem because Zombies won't face Macro that often and it can often be blown away with MST or something. The time this is a serious problem, though, is anti-cards. Yes, Chimeratech is the worst offender here. If someone has a Cyber Dragon in their Main Deck and Chimeratech Fortress Dragon in their Extra Deck when the game starts, a Machine-using opponent can start at an unfair disadvantage. Avoid anything like this that puts players at too much of a disadvantage from turn 1. It's unaviodable sometimes, but do your best.
Representation:
While writing this, I stumbled upon an article that does this section better than I would.
http://blog.ihobo.co...t-colossus.html
Basically, Cloudians would be a lot less fun to play if their names were "Archtype 12 Monster 1" "Archtype 12 Monster 2" [...ect] and their types were all "Type 4" with "Attribute 2". They would be exactly the same game-design wise, but they wouldn't be as fun because there's simply no visualisation of what they are. In Written Cards, we can easily fall into the trap of having a good, fair, game without any story, image, or anything of the sort. Preceding sets and archtype with a few paragraphs of flavor text, or adding it to the end of a card, can make a world of difference in making a card come alive to the player. It might seem trivial to some people that want nothing but balance, but it makes a world of difference to having an enjoyable set and format.
More to come when thoughts wonder into my head. This is just ideas jotted down, but I doubt I'll ever find time to tidy it up.
EDIT:
This time I'm going to cover some broader concepts and see if they can be applied to design of cards in the current format at all.
Randomness
How random should a game be? To answer that, what does randomness give to a game? Often, it closes a skill gap. Let me illustrate with an example. In a zero-randomness game where everything is known (Chess), a better player wins the vast majority of the time. In the game of coin-flip, "heads I win, tails you win." There is no skill. Does that make randomness an evil thing that makes skill meaningless? Not if it's done right. Which of these games sound most fun:
- The better player always wins. If you know they're even slightly better than you, there's no point playing against them.
- The better player is more likely to win. A pro can consistently beat a first-time player because of the skillgap, but almost-equal players have an almost-equal chance to win, and even when the opponent is a fair bit better, there's a good spark of hope.
- Any first time player can beat any pro with a good chance - there isn't much to be gained by skill or practice, you just have to play and hope.
Personally, I feel #2 sounds most fun. You want a chance, but you want to feel the games mean something and that you improve as you play more. Games are fun when you feel you out-played your opponent, but that the game wasn't pre-decided either. Translating this to Yugioh, drawing is usually random enough to reach #2, so the lesson to take away is not to make things too much more random. Inconsistent Decks, dice/coin based cards with dramatic effects, or total game-changers that can't be consistently searched, all present this risk. They're still passable if they have other good design principles, but do think about if you're making the game into coin-flip.
Options/Card Entropy
Imagine a situation. Two players are in a game, maybe around turn 3, Decks have been made about equally well, it's Player A's turn and we want to judge how skilled Player A is. What differs a skilled player from an unskilled one. Deck Design? - Well, that would make duels rather pointless, we'd just feed them into the latest DS game and let the computer decide. The answer is choices. A skilled player, when having multiple options, picks the right one. In games that aren't turn-based, mechanical aspects might come into it, but in Yugioh, we only have choices. And we like skill to be important! That's what lets you 'out-play' your opponent and lets us avoid playing that stupid game of coin-flip. So, we clearly need to give a player enough options to show their skill. What options can you make in a Yugioh game? Which cards to activate or in which order, which synchros/xyz to make with your materials, what to target with your cards, when to attack and what to attack. That seems like there would usually be plenty of choices, but consider the situation where lots of card removal has been played - you have nothing to activate in the Graveyard and your hand/field has a total of 2 cards, which you can't synchro/xyz with for some reason. How many options do you have that aren't stupid? Probably not many. The vast majority of players would make the same choices, you aren't showing any skill. Now you have a total of ten cards available and there are eight targets on your opponent's side of the field. There's probably at least five almost equally viable ways to play the hand - which one you choose is using your skill. More cards on both sides of the field usually leads to more options and more chances to prove your skill. I'm going to refer to the number of cards usable from the grave/deck, cards in your hand/field, cards in the extra Deck that have a chance to come into play, ect, as 'card entropy' a high card entropy is usually good for the game. But when can it be bad? Unfortunately for Yugioh, OTKs and Exodia mean a high card entropy can destroy player-player interaction and end the duel far too quickly if they aren't designed carefully.
How to use this carefully to better our card design then? Well, always pay attention to if your cards are increasing or decreasing card entropy. 1-4-1 destruction/negation/removal like D-Prison, Solemn, Bottomless, MST, strictly decrease card entropy (by 2 cards generally). Try and avoid things like this. We're designing two archtypes, the Happy Bunnies and their enemies, the Belligerent Badgers. Which of them has the better designed card?
|Rampaging Badgerz|
|Normal Spell|
|Activate only while you control a "Belligerent Badger" monster. Discard 1 card to send 2 cards on the field to the Graveyard.|
|Bunny Funtime|
|Normal Spell|
|Activate only whlie you control a "Happy Bunny" monster. Your opponent draws 1 card. During your End Phase, draw 2 cards.|
The Badgers really pull down the card entropy with that card, a -4 to the options! Bunnies are much nicer on the other hand, one card turns into three! A +2 to the options available, that's a card that promotes some skill! Try and leave removal to your big monsters or situational cards, and if possible, compensate the card entropy somehow, like giving your opponent a draw for each card destroyed. Even a token is better than nothing. Card removal of course, happens, but it doesn't have to be badly designed.
Comebacks
Player A is having a bad game. 3000 LP left, a set card and 2 in his hand to synchro, xyz, three backrows, two hand cards and 6500 Life Points of his opponent. Is the game over? Considering the three backrows can probably negate anything Player A tries to do with the current card pool, yes, the game is over almost every time. Should it be? Hell no! The anime doesn't put the hero behind before he wins in most of his duels out of habit. It's because comebacks are fun - when you can make a comeback, there are less Lame Duck situations. There's always a reason to keep playing. It's the opposite of slippery slope. But how do we encourage comebacks? For one, a high Card Entropy but few 1-4-1 removals are good, especially removal that can ruin a Normal Summon (Solemns, Bottomless) - when you have a high card entropy, you can combine cards in various ways - discard 1 to activate 1 then use the first one's effect from the Graveyard to summon an entirely new one from your hand and combine them to make Super-Awesome Kickass Monster, for example. If you draw Silly Spellcard as the only card on your hand or field, and still Summon Super-Awesome Kickass Monster without activating anything in the Graveyard, then Silly Spellcard is either extremely situational, or possibly overpowered enough that it adds too much luck (who draws it), especially with how hard searching spell cards can be. Generally, think about what situations a card is most likely to trigger in, and where it will have the biggest impact, and if this is good or bad for comebacks. Let's flesh out those archtypes a bit more!
|Badger Dig a Trap Hole|
|Counter Trap|
|Shuffle a "Belligerent Badger" monster in your Graveyard into your Deck to negate the Normal Summon of an opponent's monster and shuffle it into their Deck.|
|Bunny Helps People|
|Trap Card|
|Activate when a "Happy Bunny" monster on your side of the field is destroyed as a result of an opponent's attack. Return that monster and 1 monster your opponent controls to the owner's hand, then add 1 monster from your Graveyard to your hand and end the Battle Phase.|
Well, the Badger's card is going to have the most impact when your opponent needed that monster to hold on for another turn, or to start a combo that would put them back in the game, generally when they have no/few other monsters and no/few other ways to Summon monsters. That really works against comebacks, pretty bad design. I am disappointed, Badgers! Bunnies, on the other hand, are doing a great job again. The card implies that your opponent is confident enough to attack, so is probably not super-far behind, doesn't restrict your opponent's options, has a wide number of targets (any monster in your Graveyard), and generally seems much better design, good job Happy Bunnies!
"Balance" in terms of card design
Balance and design values are not the same thing, and sometimes might stand against each other. Underpowered cards are always bad design - they add more noise you have to learn to filter to make good Decks and increase clutter when searching through cards. Overpowered cards are more complicated. If there are enough overpowered generic cards that all Decks feel too similar, that's bad, but if an overpowered card fits good design principles, like encouraging high card entropy, player-player interaction, and comebacks, then it might be justified. Monster Reborn is a great example of this. It is certainly a very powerful card, but it has a greatest impact when you need a strong monster to hold on and don't have many ways to populate your field. I've seen it included in quite a few comebacks for sure, and it sets off many combos to increase card entropy. Pot of Greed is more debatable. It increases card entropy and is generally most useful when you're a bit behind, but it can simply make a format too fast and there isn't much skill to using it - you usually instantly activate it if you're lucky enough to draw it. If Exodia and other lockdowns and OTKs were removed from the format, I think PoG might quite happily sit on the limited list, albeit not perfectly designed with the luck it adds. A specific Deck (e.g. Cloudians or something) being overpowered, however, can make other Decks feel weak and make competitive players feel like they don't have much choice in Deck design. That's bad. Some overpowered cards can be justified by design, but not too many, and not too Deck-specific..
Outro
Hopefully this helps any of you planning to make cards for dueling purposes design cards which create a fun, skill-based environment for all players. If you have any points you're interested in or want to discuss, please post below! Feel free to disagree with anything above, if no-one points out when I'm wrong, it's much harder to learn.
