Riot Games is currently offering their Mystery Skins and Mystery Chests promotion in League of Legends. The event began on Thursday, Feb. 18 and will run through Thursday Feb 25.

This is a big deal, and I think we should prepare together.

What is a Mystery Skin?

Mystery Skins and Mystery Chests in League of Legends are essentially a way of gambling on cosmetic skins for your characters. You can always give mystery items as gifts to other players, but there are only a few brief periods each year when Riot allows you to buy them for yourself.

League's cosmetic skins come in five main pricing tiers: 520 RP ($4 USD), 750 RP ($5.75), 975 RP ($7.50), 1350 RP ($10), and 1820 RP ($14). There are also three ultimate skins that cost 3250 RP each, or $25.

A Mystery Skin costs 490 RP ($3.75) and gives you a random skin for a champion you own, drawn from all the skins available in these price tiers. A Mystery Chest costs 790 RP ($6) and only draws from the set of skins priced at 975 or higher. So you're saving money, but you don't get to choose what you get.

Mystery Skins and Mystery Chests can also award legacy skins, which are skins that were either only available during limited-time events, or have been removed from the normal shop for other reasons. These skins tend to be a bit rarer than the generally-available skins since you can't buy them most of the time, so they're a good way to make your champions look kind of distinct.

However, Riot makes most of the legacy skins available to purchase for at least a few weeks each year, so they're not extremely unique or prestigious.

Wait, is this a good deal?

At first glance, it seems like you're going to get your money's worth with these chests, since the chest will always cost less than the regular price of the skin. However, Riot runs constant 50% off sales on various cosmetic items, so 32 different skins are on sale each month. Mystery Chests and Mystery Skins cost less than full-price skins, but more than half-price skins. Even the legacy skins can get discounted during Riot's Christmas event.

Additionally, when you buy your skins the normal way — either at full price or on sale — you get to decide which skin you get. When you buy the Mystery Chests or Mystery Skins, you run a risk of getting skins you don't want for champs you own but don't play.

Many League players own dozens of champions, but only play a few regularly. For those players, it's probably a better plan to just buy their favorite skins for their main champs, even if they have to pay full price and those skins are expensive.

If you want a bunch of skins for a bunch of your champs, the sensible plan for the money-conscious gamer is probably going to still to shop the sales and pick out the ones you want when you can get them cheap.

If you do go for the Mystery items, what you're really hoping to get are the legendary and ultimate skins which never go on sale, or rarely-available legacy skins. The 1350 RP skins are a pretty good result from one of these as well, since only two of them go on sale each month, and there are 69 of them in the year-round store, meaning that they only go on sale about once every three years. It's a gamble.

Should you get the Skins or the Chests?

In the current store, there are 88 skins priced at 520 RP, 81 skins at 750 RP, 177 skins at 975 RP, 69 skins at 1350 RP, 20 skins at 1820 RP and 3 Ultimate 3250 RP skins. Additionally, there are 68 legacy skins at 520 RP, 27 legacy skins at 750 RP, 78 Legacy skins at 975 RP, 12 Legacy skins at 1350 and 7 legacy skins at 1820.

That means there are a total of: 156 at 520 RP, 108 at 750 RP, 255 at 975 RP, 81 at 1350 RP, 27 at 1820 RP, and 3 at 3250 RP.

I couldn't find a list of the number of skins in each price tier anywhere online, so I counted them myself from the current League store and a list of legacy skins. I rechecked my count several times, but there is still a chance — maybe even a likelihood — that I double-counted some event skins that were made permanent, or that I missed some legacy skins. If my numbers are off, please let me know in the comments, but I am pretty sure my count is close enough that I can draw some valid conclusions.

The mode of this set is 975, so the most likely result is that you'll get a 975 RP skin whether you buy a 490 RP Mystery Skin or a 790 RP Mystery Chest. Congrats! You're likely to come out ahead.

When you average the values, the expected value of a 490 RP Mystery Skin is 919 RP, and the expected value of a 790 RP Mystery Chest is 1139 RP. That means you're paying an extra 300 RP per roll to improve your expected value by only 200 RP. So, if you perceive all skins as being worth their RP cost, the 490 RP Mystery Skins are a better deal than the 790 RP Mystery Chests.

That's a pretty big caveat, though, because most players aren't very interested in the cheaper skins at all. The skins in the lower price tiers are the oldest or least elaborate cosmetic changes. Some of these visuals are four or five years old, with the lower texture resolutions and underwhelming particle effects that age implies. These skins are also unlikely to have unique ability visuals, sounds, animations and particles, and the changes to the base models are generally going to be a lot more modest.

On average your investment will likely pay off, but you could be stuck with something that feels like garbage. Be aware.

There are a couple of cool skins in the cheaper tiers — I'm particularly partial to the 520 RP skin which turns time-mage Zilean into a hippie, the one that turns Master Yi into an off-brand Jedi, and the line of 750 RP "debonair" skins that dress various characters in white tuxedos. But in general, you're going to get underwhelming skins from this pool. Knocking the 520 RP and 750 RP skins out of the pool of possible skins also nearly doubles your odds of getting a 1350 RP or higher skin.

The bottom line is that if you're looking to feel like you saved the most money over the sticker price of whatever you get, the 490 RP Mystery Skins are a better value by that metric. However, if you find the cheaper skins unappealing and you want better odds of getting the really fancy ones, you may find it is worth upgrading to the 790 RP Mystery Chests.

Personally, I went for the Chests.

Tips for improving your results

Keep in mind that you can only get skins for characters you own out of Mystery Skins and Mystery Chests, so the odds for your champion pool may be a bit different than the odds for the total set of characters. You can slant things slightly in your favor by making sure you own the champions with the fanciest customizations.

This system actually works to the benefit of players with smaller champion pools. If you own only five or six champions and three of them are Sona, Udyr and Ezreal, who have Ultimate skins, your odds of getting one of those is going to be a lot higher than the odds for a player with 130 champs. Some players actually roll new League accounts with just a few champs to try to get cheap ultimate skins via Mystery Skins.

Hypothetically, if you had a very small pool of champions and every one of them had a legendary or ultimate skin available, your odds of getting a legendary or ultimate customization from a Mystery Chest could be as good as around one in three.

However, planning your champion lineup around Mystery Skins is an extreme thing to do, and if you’re a current League player, it’s probably already too late for you to do this unless you want to start a new account.

It is, however, important to keep in mind that the more champs you own with legendary skins, the better your odds of getting one are, and if you don’t own the three characters who have ultimate skins, your odds of getting an ultimate skin drop to zero.

Riot has been releasing a lot more expensive skins recently, and they haven’t made any 520 skins for several years. If you have a lot of older characters and are missing a lot of the newer, more expensive ones (which is likely to be the case for most players), the skin pool for the champions you own is also likely to be tilted more heavily toward the cheaper skins than the overall set of characters’, which means you might want to consider buying the 790 RP Mystery Chests to avoid getting those.

Real-World Mystery Chest Results

Okay, so, in the interest of science, and because I have very little self-control, I bought 30 790 RP Mystery Chests, which cost $158, after factoring in the Bonus RP I got for buying in $100 increments. So, I can now share my results with you, and give you a less esoteric idea of what you'll get if you buy a bunch of these.

I have 52 champions, and was eligible for all the Ultimate skins, but I already owned two legendary skins, and I am missing 7 champs with legendary skins available, meaning I was eligible for only 11 current legendaries. Here's what I got:

3250 RP Ultimate skins: None.

1820 RP Legendary Skins: Aether Wing Kayle; Demonblade Tryndamere.

1350 RP Legacy Skins: Slayer Jinx

1350 RP Skins: Spirit Fire Brand; Void Bringer Illaoi; Eternum Rek'sai; Blade Queen Lissandra; iBlitzcrank; Risen Fiddlesticks; Sad Robot Amumu; Pool Party Graves; Mecha Malphite

975 RP Legacy Skins: Unmasked Kayle; Professor Ryze; Championship Thresh; Headmistress Fiora; Toy Soldier Gangplank; Bad Santa Veigar

975 RP Skins: Woad King Darius; Hextech Janna; Dragonslayer Braum; Ionia Master Yi; Guquin Sona; Pentakill Sona; Full Metal Rammus; Dragonslayer Vayne; Superb Villain Veigar; Dark Valkyrie Diana; Sultan Tryndamere; Surprise Party Fiddlesticks

This list has several clear highlights: The legendary skins are obviously cool; Championship Thresh is a popular and coveted skin that is rarely available; Headmistress Fiora looks like the porn-parody version of Sarah Palin, which I think is hilarious; Slayer Jinx, Pool Party Graves, Void Bringer Illaoi, iBlitzcrank and Mecha Malphite are very cool skins for champs I often play. I haven't spent much time with Fiddlesticks, but the Surprise Party skin turns his crows into balloon dogs, and the skin has a bunch of party-horn sound effects. I love it.

There are also several low points in this group of skins, however: I got two Veigar skins. I rarely play Veigar, I am unlikely to ever want to dress him up as Santa, and he has a legendary skin themed around making his spells look like effects from SNES-era games, which is cooler than either of these. I also got two Sona skins, but neither of them is THE Sona skin.

I got Woad King Darius and Hextech Janna, when I already owned the Dunkmaster Darius and Forecast Janna legendary skins, so I probably won't use these much. I'm also probably not going to get much use out of the Sultan Tryndamere skin or the Unmasked Kayle skins, since I got their legendaries.

The Eternum Rek'Sai skin is cool, but I already had a Pool Party Rek'sai. I like Rek'sai, so I might use both of them sometimes, but I didn't really need another skin for her.

All told, the full-price cost of these skins is 38,330 RP, and I paid 23,700 for them. If I had gotten all the 975 and 1350 skins on sale, I would have spent only 19,156 RP for them, however, and saved about $30. As I pointed out earlier, you can wait years to get 1350 RP skins on sale, and some of the legacy skins don't go on sale at all, so that may be an unfair comparison, but I probably wouldn't have bought some of the skins I got from these chests under any other circumstances, even if they were half-price.

For comparison purposes, here is a Redditor's log of his results from buying 58 Mystery Skins at 490 RP each.

Other comparisons: For the same amount of money I spent on 30 chests, I could have bought all three Ultimate skins and had enough left to buy 7 legendary skins, and I'm fairly convinced that, if your goal is to collect the legendaries, you'll spend more money fishing for them in Mystery Chests than you will buying them outright.

Opening Mystery Chests was fun, but I could have done the dew, y'all

I also could have bought 24 of the most expensive champions at full price, or 48 expensive champs on sale (there are actually only 32 champs in the highest price tier). There's an argument that it's pretty dumb to spend a bunch of money on skins in LoL when I still have a lot of champs to collect, but realistically, nobody plays more than a couple of dozen champs regularly, and, as I explained above, Mystery Chests actually give somewhat better odds to players with smaller collections.

With my $158, I could have gone to see Deadpool 11 times. Or, I could have bought two full-price PS4 games and a couple of cases of Mt. Dew to drink while I played them. Opening Mystery Chests was fun, but I could have done the dew, y'all. #puppymonkeybaby (Editor's note: I hate you.)

Of course, there is always going to be a contingent that feels that spending money on cosmetics is wasteful; skins have no practical impact on the game. Ultimately, how you value this stuff is subjective.

Your Mileage May Vary

Okay, here's the quick, TL;DR, because this was admittedly pretty L:

Mystery skins and chests are currently the only way to get most "legacy" skins outside of the short windows each year when Riot makes them available.

Mystery Skins and Chests will always give you a discount off the full price of the skin you get, but you'll still usually pay more than you'd pay if you bought the skin during a 50% off sale.

490 RP Mystery Skins will end up giving you a better total discount off the sticker price, but buying 790 RP Mystery Chests gives you better odds at the fanciest skins and prevents you from getting the cheap ones that nobody wants.

The odds of getting any given skin are low, so if there's something specific you really want, you are probably better off just buying it.

Being patient and waiting for the stuff you want to go on sale is the best way to get the best deals in League of Legends, but you sometimes have to wait months or even years to get those deals. If you're into instant gratification and you're not particular about which skins you get, Mystery Chests or Mystery Skins are a much better bargain than paying full price.

That said, Hextech Crafting, a new system that allows you to gamble on chests containing random items, is going to be available in the next few weeks. This system will let you buy a new kind of chest that will contain "shards" of different champions and cosmetics, and you'll be able to dismantle the ones you don't want to get "essences" that can be used to upgrade the ones you like into permanent items, kind of like the crafting system in Hearthstone.

We won't know whether the Hextech chests offer better values than Mystery Skins and Mystery Chests until the new system goes live, but it is potentially telling that Riot recently increased the daily limit on Mystery Skins/Chests to 10, when the cap used to be 5. I don't know if the increased daily limit on Mystery Skins is connected to the upcoming system, but I do know that if the Hextech crafting turns out to be a much better deal, I'll be kicking myself next month for dropping so much cash on Mystery Chests.

If you're buying Mystery Skins or Chests, please share your results in the comments, and if you have a different view about the value you get from playing this slot machine, feel free to sound off.