Needs to be removed.
It makes sense that 
is great in URF; 80% cdr and each spell cast adds 20 stacks regardless if it hits a target or not.
When is bought by 6/10 champions three games in a row, it's pretty clear that this item is utterly broken on URF.
The most outstanding abuser: 
can proc Luden's twice per second without breaking a sweat. From 2000 units away.
RussoRed2 votesurf is a joke it doesent have any blanance remeber that
MaizeCraze2 votesYes that's why Riot decided to put out balance changes this year specifically for URF.
DrCyanide3 votesAnd those changes where made to prevent removing/disabling items, champions and summoner spells.
Also, in the five URF games I've played, Luden's hasn't been bought more than four times per match. I'm not saying either sample is representative, just that you can't go on 2 games and call an item OP because of it.
MaizeCraze1 votesThose were the most prominent examples. I have played 10 game of URF so far; 35 were bought.
Least: 0(1)
Most: 6(3)
Mean: 3.5 (round to 4 per game)
If an item appears in a game on 40% of champions, isn't that telling you that something is wrong?
DrCyanide1 votesNo, not really. If Luden's wasn't there you'd have 40% picking a Deathcap, and if Deathcap wasn't there you'd have 40% buying Zhonya's.
All these stats simply mean you've got 40% of the players picking mages and prioritizing one damage item over the others they plan to get.
MaizeCraze1 votesWhile arguably all mages will get Deathcap every game (regardless of mode), in non-urf SR is picked much more infrequently.
In Diamond solo queue, Luden's has a popularity ranging from 5-7% of games. That means it is purchased by one champion approximately every other game. Therefore, it can be said that Luden's is purchased by one out of four mages.
Also in diamond solo queue, deathcap has 22% popularity. This means 100% of ap mids purchase deathcap. In URF, that number is slightly lower due to games finishing much faster, but it can be inferred that deathcap would be purchased on 100% of mages who built like an ap carry if they had the necessary time.
In my 10 games of URF, there were 47 mages who built like an ap carry. Out of those 47, 32 were purchased. That is a 69% pick rate compared to a 25% in ranked SR. Meanwhile, Rabadon's sees no increase or decrease, staying stable around 100%.
The other three Luden's were purchased on 
, 
, and 
(built only two damage items).
DrCyanide1 votesI'd like to point out that neither of us are in Diamond, so comparing our URF games to Diamond ranked games is a very far stretch. If you compared Diamond URF games to Diamond ranked games, or Silver URF games to Silver ranked games, then I'd be more convinced. Even then, the stats will be biased because URF doesn't have a jungler or support, but rather an extra APC or two, meaning you should compare the purchase rate per APC rather than the purchase rate per game.
You might still be on to something, and Luden's might be OP, in just saying the stats you've pulled so far aren't very convincing.
MaizeCraze1 votesI did compare APCs, and I took out the bias (1 in 5 champions should be an APC). From my post above, you can see that I factored in only the APC's in ranked games.
Luden's has a popularity ranging from 5-7% of games. That means it is purchased by one champion approximately every other game. Therefore, it can be said that Luden's is purchased by one out of four mages.
Also in diamond solo queue, deathcap has 22% popularity. This means 100% of ap mids purchase deathcap.
In addition, I only counted APC's in my games of URF thus far.
stats for solo queue silver:
Luden's is picked about 5% of the time. Rabadon's is picked about 21.5% of the time.
This shows that pick rates for Luden's and Deathcap in Silver and Diamond are essentially analogous.
disregardable1 votesHonestly, I just build it because it builds out of 
. No point in bringing Doran's Ring, so I take that instead.
Battleforge4Life1 votesI usually get 
first but is a close second.
KnivingDude1 votesLuden's in Urf?
Anti-mage 
.
Squidblimp1 votesIt's URF. Forget about balance, lol.
Sailor Mint1 votesLuden's is a strong first or sixth item. You don't need MP5 and CDR on URF, so you stack raw AP items right off the bat.