<p>Looking at the Yu-Gi-Oh wiki and they have a section on tournament that covers marked cards and it appears to only be concerned about identifying the card without needing to see the front of the card. I have also found some specific topics regarding the penalties for marked cards and a topic just defining what one is.</p>

<p>From what I can see the front is not as important as long as the normal text on the card isn't interfered with (so players know what it does) and the card can't be identified while it is in the deck that marking them on the front should not be an issue.</p>

<blockquote>
  <p>A card is considered to be marked if it can be identified without seeing the front of the card. This includes but is not limited to warping, creases, discoloration, card thickness or texture, and water-marks. Ifthe cards are sleeved, this includes but is not limited to sleeves with identifying marks or other unique characteristics that distinguish it from other cards in the Deck. Cards that have been physically altered to add or subtract layers of foil, etc, are not legal for Sanctioned tournament play.</p>
</blockquote>

<p><a href="http://yugioh.wikia.com/wiki/Tournament_Rules" rel="nofollow noreferrer">http://yugioh.wikia.com/wiki/Tournament_Rules</a><br>
<a href="http://yugioh.wikia.com/wiki/Marked_Cards" rel="nofollow noreferrer">http://yugioh.wikia.com/wiki/Marked_Cards</a><br>
<a href="http://yugioh.wikia.com/wiki/Marked_card" rel="nofollow noreferrer">http://yugioh.wikia.com/wiki/Marked_card</a></p>

CC BY-SA 4.0
2018-08-21T17:11:08.860Z
Although the wiki is *great* reference, sometimes an Official YGO source is better and more accurate ... please refer to my [edited answer](https://boardgames.stackexchange.com/a/43221/22373) were we can see that marking is indeed not allowed on official games
DarkCygnus
CC BY-SA 4.0
2018-08-21T17:25:26.027Z
@DarkCygnus is correct and his answer with an official source (Which I had issues finding) is better then my wiki answer.
Joe W
CC BY-SA 4.0
2018-08-19T21:03:15.513Z
2018-08-19T21:03:15.513Z
Joe W
<p>Mark the outside of your sleeves. If a specific tournament has a problem with it you, can replace the sleeves with unmarked sleeves, you won't devalue your cards. Magic the gathering has a similar issue with "altered cards" that is cards where the art has been modified in some way. Generally as long as the alter doesn't interfere with your opponent's ability to read the card, or tell what it is it will probably be fine, but since you're just looking for a play aide sleeves will allow you to do so while still being able to switch to no marks if you run into a strict judge. Just make sure your deck is checked beforehand, as if there's a complaint mid tournament you're more likely to be disqualified or get a game loss...</p>

CC BY-SA 4.0
2018-08-20T14:03:19.977Z
2018-08-20T14:03:19.977Z
aslum
<p><strong>Edit:</strong> As promised, here is a quote from the <a href="https://www.yugioh-card.com/lat-am/gameplay/penalty_guide/Yu-Gi-Oh_Tournament_Policy_05May11.pdf" rel="nofollow noreferrer">Yu-Gi-Oh! tournament Policy</a> regarding altered cards, emphasis mine, where we can see that in fact marked cards may not be used in tournaments:</p>
<blockquote>
<p>Cards that have been altered from their original appearance with surface decoration may be used for play only if the alterations  do  not  obscure  any  portion  of  the  card text,  make  the  illustration  difficult  to  recognize, or  make  the  card distinguishable from other cards in the Deck while it is face-down.</p>
<p>The  <em>Head  Judge  of  the  event  has  final  arbitration</em>  on  whether  or  not  altered  cards  may  be  used  at  the  tournament. Duelists are responsible for determining whether or not their altered cards are acceptable for use before the start of the tournament.</p>
<p><strong>Cards  with  any markings  added  on the  front or  back,  may  not  be  used  in  any  Yu-Gi-Oh!  TRADING  CARD  GAME World Championship tournament</strong></p>
</blockquote>
<hr />
<p>(Original answer)</p>
<p>In casual and friendly games not, however on official games or tournaments:</p>
<blockquote>
<p>Are there any rules against this? Does it make the card in any way illegal or unplayable?</p>
</blockquote>
<p>In a way, it could depend on what that mark is (that is, if it is noticeable by others). But anyways, all <strong>marks on cards are not allowed on official games.</strong></p>
<p>In fact, when you assist an official tournament Judges first go through your Deck list, checking you indeed have and use those cards.</p>
<p>While on that, they also check to see <strong>if any card you own has marks or is in bad shape</strong>. They do this as marking cards is considered cheating, as you could easily stack or track them, or do some other dishonest tactic.</p>
<p>If they find any such card, damaged or marked, they will <strong>ask you to get a mint, near-mint card</strong> to replace it, or well drop it from your Deck.</p>
<p>If, during the tournament you are caught with marked cards, it could mean game loss for you, or even dropping from the contest.</p>
<blockquote>
<p>As a bonus: can I do this to the (inside) of the sleeve instead?</p>
</blockquote>
<p>Again, could give room to cheating and stacking cards. Having a thicker card will make it stand out from the others, and you could strategically place it on top of your Deck or similar deceptive moves.</p>
<p>Furthermore, card sleeves must be identical on all your Main Deck cards, and also be in good shape. Cards on your Extra Deck should be in the same condition and have a <em>different</em> color that your Main.</p>
<hr />
<p>That being said, marking your cards will also affect it's value and price, so you may be losing money if doing so.</p>
<p>I'd say it's on your best interest to <strong>learn your archetypes and card rulings</strong>, instead of having to mark your cards. Eventually you will come to know them perfectly, and will regret having marked your cards.</p>

CC BY-SA 4.0
2018-08-21T17:07:09.777Z
@JoeW edited my answer and added a solid official YGO (not wiki) reference if you mind reconsidering... I'd also say we could clean a bit all the comments here now that reference backing up the answer has been added
DarkCygnus
CC BY-SA 4.0
2018-08-21T22:42:05.770Z
The quote you added... The first paragraph says yes and the last says no...
Weckar E.
CC BY-SA 4.0
2018-08-21T23:42:14.567Z
@WeckarE. I think that not exactly, on the first part they say "their appearance". This most likely refers to those players that like to "draw" over their cards, or customize (with nail polish ,and other stuff) the art or appearance of the illustration... the last part says "with markings", and also says on Official YGO Tournaments. The first part does not specify the tournament thing, suggesting perhaps that in non-tournaments you could use them. Finally, it states that the call comes down to the Head Judge to decide if it's playable or not...
DarkCygnus
CC BY-SA 4.0
2018-08-22T01:11:47.153Z
@WeckarE. I think the last paragraph is talking about a specific tournament and not tournaments in general.
Joe W
CC BY-SA 4.0
2018-08-23T10:47:47.173Z
@JoeW It does read that way. Not all tournaments are World Championship are they? That'd be silly... I do appreciate the research, though, just trying to get it in context!
Weckar E.
CC BY-SA 4.0
2018-08-19T17:30:46.923Z
2018-08-21T17:05:46.557Z
2020-06-17T09:01:24.697Z
DarkCygnus
<p>I have been running a set of cards for a while (Flower cardian) where the summoning of some forbids the summoning of out-of-archetyle cards after them, and some do not.</p>

<p>In order to help me remember, I was planning to put a mark on the face of the cards that still allow it.</p>

<p>Are there any rules against this? Does it make the card in any way illegal or unplayable?</p>

<p>As a bonus: can I do this to the (inside) of the sleeve instead?</p>

CC BY-SA 4.0
2018-08-19T17:06:31.993Z
By Mark you mean?
DarkCygnus
CC BY-SA 4.0
2018-08-20T14:12:41.257Z
@DarkCygnus Probably a small marker dot, text highlighting or removable sticker depending on what is more practical.
Weckar E.
CC BY-SA 4.0
2018-08-21T17:06:32.840Z
I edited my answer and included a reference, for you to consider it's usefulness now :)
DarkCygnus
<yu-gi-oh>
Is modification of the face of a card legal?
Weckar E.
# Is modification of the face of a card legal?

(Asked by: username_0 on 2018-08-19)

I have been running a set of cards for a while (Flower cardian) where the summoning of some forbids the summoning of out-of-archetyle cards after them, and some do not.

In order to help me remember, I was planning to put a mark on the face of the cards that still allow it.

Are there any rules against this? Does it make the card in any way illegal or unplayable?

As a bonus: can I do this to the (inside) of the sleeve instead?

**Tags:** yu-gi-oh

> **Comments:**
> **username_1**: By Mark you mean?  
> **username_0**: @username_1 Probably a small marker dot, text highlighting or removable sticker depending on what is more practical.  
> **username_1**: I edited my answer and included a reference, for you to consider it's usefulness now :)  

---

## 3 answers

### Answer by username_2 on 2018-08-19. Score: 4

Looking at the Yu-Gi-Oh wiki and they have a section on tournament that covers marked cards and it appears to only be concerned about identifying the card without needing to see the front of the card. I have also found some specific topics regarding the penalties for marked cards and a topic just defining what one is.

From what I can see the front is not as important as long as the normal text on the card isn't interfered with (so players know what it does) and the card can't be identified while it is in the deck that marking them on the front should not be an issue.

> A card is considered to be marked if it can be identified without seeing the front of the card. This includes but is not limited to warping, creases, discoloration, card thickness or texture, and water-marks. Ifthe cards are sleeved, this includes but is not limited to sleeves with identifying marks or other unique characteristics that distinguish it from other cards in the Deck. Cards that have been physically altered to add or subtract layers of foil, etc, are not legal for Sanctioned tournament play.

<http://yugioh.wikia.com/wiki/Tournament_Rules>  
<http://yugioh.wikia.com/wiki/Marked_Cards>  
<http://yugioh.wikia.com/wiki/Marked_card>

> **Comments:**
> **username_1**: Although the wiki is *great* reference, sometimes an Official YGO source is better and more accurate ... please refer to my [edited answer](https://boardgames.stackexchange.com/a/43221/22373) were we can see that marking is indeed not allowed on official games  
> **username_2**: @username_1 is correct and his answer with an official source (Which I had issues finding) is better then my wiki answer.  

---

### Answer by username_3 on 2018-08-20. Score: 2

Mark the outside of your sleeves. If a specific tournament has a problem with it you, can replace the sleeves with unmarked sleeves, you won't devalue your cards. Magic the gathering has a similar issue with "altered cards" that is cards where the art has been modified in some way. Generally as long as the alter doesn't interfere with your opponent's ability to read the card, or tell what it is it will probably be fine, but since you're just looking for a play aide sleeves will allow you to do so while still being able to switch to no marks if you run into a strict judge. Just make sure your deck is checked beforehand, as if there's a complaint mid tournament you're more likely to be disqualified or get a game loss...


---

### Answer by username_1 on 2018-08-19. Score: 2

**Edit:** As promised, here is a quote from the [Yu-Gi-Oh! tournament Policy](https://www.yugioh-card.com/lat-am/gameplay/penalty_guide/Yu-Gi-Oh_Tournament_Policy_05May11.pdf) regarding altered cards, emphasis mine, where we can see that in fact marked cards may not be used in tournaments:

> Cards that have been altered from their original appearance with surface decoration may be used for play only if the alterations do not obscure any portion of the card text, make the illustration difficult to recognize, or make the card distinguishable from other cards in the Deck while it is face-down.
>
> The *Head Judge of the event has final arbitration* on whether or not altered cards may be used at the tournament. Duelists are responsible for determining whether or not their altered cards are acceptable for use before the start of the tournament.
>
> **Cards with any markings added on the front or back, may not be used in any Yu-Gi-Oh! TRADING CARD GAME World Championship tournament**

---

(Original answer)

In casual and friendly games not, however on official games or tournaments:

> Are there any rules against this? Does it make the card in any way illegal or unplayable?

In a way, it could depend on what that mark is (that is, if it is noticeable by others). But anyways, all **marks on cards are not allowed on official games.**

In fact, when you assist an official tournament Judges first go through your Deck list, checking you indeed have and use those cards.

While on that, they also check to see **if any card you own has marks or is in bad shape**. They do this as marking cards is considered cheating, as you could easily stack or track them, or do some other dishonest tactic.

If they find any such card, damaged or marked, they will **ask you to get a mint, near-mint card** to replace it, or well drop it from your Deck.

If, during the tournament you are caught with marked cards, it could mean game loss for you, or even dropping from the contest.

> As a bonus: can I do this to the (inside) of the sleeve instead?

Again, could give room to cheating and stacking cards. Having a thicker card will make it stand out from the others, and you could strategically place it on top of your Deck or similar deceptive moves.

Furthermore, card sleeves must be identical on all your Main Deck cards, and also be in good shape. Cards on your Extra Deck should be in the same condition and have a *different* color that your Main.

---

That being said, marking your cards will also affect it's value and price, so you may be losing money if doing so.

I'd say it's on your best interest to **learn your archetypes and card rulings**, instead of having to mark your cards. Eventually you will come to know them perfectly, and will regret having marked your cards.

> **Comments:**
> **username_1**: @JoeW edited my answer and added a solid official YGO (not wiki) reference if you mind reconsidering... I'd also say we could clean a bit all the comments here now that reference backing up the answer has been added  
> **username_0**: The quote you added... The first paragraph says yes and the last says no...  
> **username_1**: @WeckarE. I think that not exactly, on the first part they say "their appearance". This most likely refers to those players that like to "draw" over their cards, or customize (with nail polish ,and other stuff) the art or appearance of the illustration... the last part says "with markings", and also says on Official YGO Tournaments. The first part does not specify the tournament thing, suggesting perhaps that in non-tournaments you could use them. Finally, it states that the call comes down to the Head Judge to decide if it's playable or not...  
> **username_2**: @WeckarE. I think the last paragraph is talking about a specific tournament and not tournaments in general.  
> **username_0**: @JoeW It does read that way. Not all tournaments are World Championship are they? That'd be silly... I do appreciate the research, though, just trying to get it in context!  

---

