Before posting a question here:

Check Netrep or Yu-Judges which is the official site for the Yu-Gi-Oh! TCG Card Game Rulings

Here is the link for Netrep
Here is the link for Yu-Judges

NETREP is the site that has all the Official UDE FAQ/Rulings in its Database and it has a better interface unlike the UDE FAQ Website. It usually Answers most of the Common Questions that we all get regarding a certain Situation in a duel/card effect.

It also gives you more information like the Set Number and the Pack in which you can find a certain card. Its not necessary that you know the entire and correct card name, just a part of it is Enough. Ex. You want to search for the Continuous Trap card called "Royal Decree". In this case you can just type, "Royal" or "Decree" or "cree" or "oyal" as well in the Name Contains Field. It will show you a list of cards having the characters as a part of the name of the cards. There may be More than 1 card in the list, so check for the card u need by clicking on the Names in the List...!

Recently Netrep has changed its server twice and many people had a problem checking the Rulings, so if you are offline and/or unable to check Netrep, then you can download this Program Called RONIN(Rulings Online Network Information Node), and after downloading and installing it, just go to the file menu and click on Enable Offline Mode. The Program will download the rulings for once and then you will be able to check them while you are offline as well as it has the same database as that of Netrep since Mark Daniel Martinez owns both of them. You can update it around once a week or so if you want to....

Here is the link for RONIN

Never Trust The Rulings or Card Text from Yu-Gi-Oh! Wikia, just check NETREP and if you don't find that card in NETREP Database, then ask here and we will answer Smile

~ Credits go to Yusei fudo or lord sesshoumaru for this explaination.