Joseph has been playing Yu-Gi-Oh! Duel Links since 2016, as well as the Yu-Gi-Oh! TCG since 2001.
If you have played Duel Links for any amount of time, you know just how much of a grind it can be to acquire new cards, and how annoying it can be to not get the card(s) you were chasing after. The typical way to obtain new cards is through the use of Gems (the in-game currency), or real money, to buy packs of three random cards from the Shop. However, there are cards that are not available through this method, and for those you will have to duel against the Legendary Duelists.
Legendary Duelists can be found at the Gate in each Duel World, and dueling against them requires two resources—normal Gate Keys, and colored Gate Keys. The normal Gate Keys are used for every Legendary Duelist, whereas colored Gate Keys are used for specific characters. These come in six colors:
So for example, a duel against Yuya Sakaki will require normal and green-colored Gate Keys, but a duel against Gong Strong will require normal and white-colored Gate Keys. The required number of each resource also increases with the level of the Legendary Duelist.
Note: Legendary Duelists can appear outside the Gate like a Standard Duelist and it does not cost any resources to duel against them. They spawn infrequently and it is random who will appear, so it is not a reasonable method for grinding rewards.
As you can see from the graphic above, the cost to duel against the higher level versions of each of the Legendary Duelists is quite expensive, so why do it? The reason is the list of possible rewards from defeating them is narrowed down to their unique cards. This makes it easier to obtain Ultra Rares (URs) and Super Rares (SRs). Just take a look at a comparison between Zuzu at Level 10 versus at Level 40.
Duel Assessment Rewards
The main way you will be earning Gate Keys is through Duel Assessment rewards after each duel whether you win or lose. You get a reward drop for every 1,000 points you get, but not every reward drop is guaranteed to be a key drop, although they are fairly common.
Each time you get a Gate Key drop, it will either be 13 normal or 8 colored ones. This means that if you want to duel a single time against a Level 40 Legendary Duelist, you will need to obtain 7 colored Gate Key drops as well as 8 normal Gate Key ones.
On average you will earn 3-4 rewards per duel that you win, unless you are using a deck geared specifically for higher assessment scores. There is also a "Results Booster" item that will increase your Duel Assessment score by 1,000 for a single duel, but you typically want to save this item for duels against Legendary Duelists for an extra chance at a UR or SR card drop.
Double Key Events
There are also Double Key events that, as the name implies, doubles the keys that you get from reward drops. These events are the best way to farm keys, and you should take advantage of them when they occur. They usually last about a week, so by consistently keeping up with dueling against Standard Duelists throughout the event, you should end up with a considerable pile of keys.
You can also use Duel Orbs to spawn all of them back after defeating them, which can help to speed up the grind. However, Duel Orbs are hard to come by, and you need 10 of them in order to immediately respawn the Standard Duelists, so waiting for Double Key events is the best way to make use of them.
Trader and Stage Missions
You can also trade in 1,000 normal Gate Keys at the Trader to get 100 colored Gate Keys. You can do this once for every color before having to wait eight hours for the Trader's stock to reset. Keep in mind before you do this that you use normal Gate Keys for every Legendary Duelist, and the required amount is higher per duel than colored Gate Keys, meaning that you will burn through them quicker.
Another way to obtain Gate Keys is through completing Stage Missions in each Duel World. You won’t necessarily be swimming in Gate Keys by just doing Stage Missions, but it is something to keep in mind.
Master Gate Key
If you find yourself staring down the start of a KC Cup, and you really need a couple more cards from a Legendary Duelist to complete your deck, you can always purchase (with real money) a Master Gate Key.
The Master Gate Key will make it so that for 30 minutes you do not have to use any of your Gate Keys (normal and colored) in order to duel against a Legendary Duelist. If you are able to average three minutes per duel—which is pretty quick considering you have to reenter the Gate each time you wish to duel—you can duel about 10 times per Master Gate Key activation.
That may sound like a deal, but keep in mind that short duels typically mean a lower Duel Assessment score, which gets you less rewards and less of a chance at getting the UR or SR drop you are chasing. It is better to build a specific "farm" deck for the Legendary Duelist you wish to duel that will ideally give you 8,000 points per duel, which will get you the max number of rewards.
SR and UR Tickets
The final thing to keep in mind is the use of your SR and UR tickets. If you are having an especially difficult time earning the card you want, then you can make things easier by exchanging one of your Tickets for the desired card.
Only do this if you are absolutely sure in your decision as SR and UR Tickets are hard to come by; they are usually only given out during events. Tickets expire after a few months (or in some instances a full year), so there is no rush to immediately use them. Try and acquire the card(s) you want through dueling against the Legendary Duelists before exchanging your Tickets.
A Few Final Tips
It all comes down to the grind—and a bit of luck—when collecting Gate Keys. There are a few things you can do to help optimize that grind though.
First off, I suggest trying to keep a minimum of at least 1,000 of each colored key on hand at all times in case a new character is released and they have a meta changing card or two as reward drops. You don't want to be stuck grinding for Gate Keys while everyone else is already getting SR and UR drops from the new character.
You should also log in periodically throughout the day and duel against as many Standard Duelists as you can as it takes them a while to respawn after dueling them. Unless you are willing to spend money, you won't be able to amass a large amount of Gate Keys in just a day or two, so keeping up with your Standard Duelists daily is vital.
When you complete all Stage Missions for the current Duel World level, it will automatically respawn all Standard Duelists. If you have any Standard Duelists active in your Duel World, go ahead and duel against them before claiming the last Stage Mission reward.
Finally, try to build a good "farm" deck for the Legendary Duelist you want to duel against. This deck should aim to get the max Duel Assessment score which will make the grind more cost efficient.
If you have any questions, or if I missed anything, leave a comment down below.
Good luck, Duelists!