Newbie tip: Purchasing RP for the first time? Consider buying an IP boost first.
You promised yourself when you started playing League you wouldn't fall into the mindless spending your peers have. There's a lot you could have done with the $200 your best friend easily threw away for some virtual currency and a handful of useless cosmetic changes. But months in you've started to feel pretty lame having tier 5 mastered your favorite champion without a custom skin to express yourself. So, internally struggling, you've finally decided to make the gut wrenching decision to completely throw away $20 into purchasing RP for the first time. Those pretty skins have been taunting you for months now and you're going to be able to dance around with confidence knowing that every enemy you spam laugh to oblivion is jealous of your new dreads. But here's the thing about skins... especially if it's brand new, they're mostly here to stay. I understand if you're buying RP to get the elusive making-a-brief-appearance-from-the-legendary-vault skin or there's a deep sale on a 3000+ RP ultimate skin (which is $35 spent at the minimum and fucking ridiculous, by the way). But if you're willing to wait, your first RP purchase should probably be invested into beefing up your game. I'm talking about IP boosts.
IP is the only currency that can purchase runes, but if you are adamant about not spending any money on League's RP, the slow incremental growth of IP is your only avenue for buying champions and the convenience of additional rune pages. If you do start using RP, it has always been highly suggested to use your RP for champion and rune page purchases over the optional IP, as the value ratio between the two currencies express that IP prices are highly inflated. So this post is only condoning the purchase of runes with your IP.
League is still plagued with many oversights. The game is one of the most popular games in the world while also being the least newbie-friendly. The tutorial is ridiculous and 90% of the most widely accepted tips aren't available to you unless you have a good friend to show you the ropes or you obsess about asking questions online before you act. In my opinion, one of the biggest guidelines for new players (that is otherwise practically impossible to just stumble upon) is to not spend a single point of your IP until tier 3 runes are unlocked at level 20. After that, you still only have two rune pages where additional rune pages cost more IP than many champions cost, and if you aren't going to spend even a dollar on the game, unlocking the champion(s) that fit your playstyle is still additional IP. Assuming you don't spend a point of that IP during your journey to level 20, the ~15k-20k you collect by then will be able to buy you enough runes for one typical AD or AP playstyle, but then you're back close to zero with thousands of IP needed to fund additional runes for other playstyles. With the amount of runes you need to complete a full page, their price, and how many are required to be able to maintain playstyle diversity (instead of being forced into a situation where you are playing an AD champion with AP runes), the slow IP earn rate frustrates many newer players eager to try new things.
Using your RP to purchase an IP boost doubles, and sometimes triples (depending on how well you do), the amount of IP you'd normally get per game, allowing you to fund your rune collection in a shorter amount of time. While skins are pretty, and definitely worth purchasing in the future, consider purchasing an IP boost first to help get your account stocked with the runes you'll need to be effective in battle.
What's more effective? The expiring IP boost or the per win IP boost? This completely depends on how much time you spend playing League. For my best friend, who puts in 4-8 hours of League five days a week, the expiring boost suits his needs because of how often he plays. For me, someone who gets to play maybe ten games per week, the per win IP boost fits my needs because they never expire. My best friend will eat through a 50-win IP boost in a little less than two weeks, while a 30-day IP boost would have continued to benefit him long after.
Side note: There is also an experience (XP) boost available to help get your account to level 30 as fast as possible. While this sounds appealing, it's typically not a good idea to purchase these as a new player, or for someone who isn't going to sink more money into their account to add an IP boost with it.
**1.) **If you're new, getting to level 30 in a lesser amount of time removes valuable learning experience. While you are matched in your games based on a win/lose score so that player skills can be attempted to be matched, you risk playing against an opponent with more games (and therefore more experience) because they didn't use an XP boost. It's best to level up the slow way to get accustomed to the game's many facets.
2.) Using an XP boost, again, means less games played in order to get to level 30. And less games played means less IP gained by the time you can start purchasing tier 3 runes. Unless you're also purchasing an IP boost to help mitigate the difference, XP boosts rob you of IP points.
That's all I have for now. Happy gaming :)
