There are champs like 
where you can get away with 1st timing but holy sh*t stop trying to use Shaco in ranked with little to no practice. I played him a countless number of times in EVERY game mode before even thinking to play him in ranked. You aren't going to do well without some stroke of luck.
It makes me cringe like no other when people do this it makes me want to rip my eyes out
Sukishoo10 votesNever 1st time anything in ranked without play before hand.
rinsujo2 votesI first time support Nunu'd once.
It did NOT go well.
ABlueQuaker1 votesProbs cos you didn't run Challenging Smite + Cinderhulk like a pleb. That sh*t is legit af.
rinsujo1 votesI did not, as neither of those things existed S3. Haven't made the mistake of first-timing a champ in ranked since then. Haven't tried cinderhulk on nunu yet though, i feel like in jungle Magus is stronger because dat ap.
Rew7111 votesI did that with 
top... lets just say I didn't even know how to build.
PL551 votesI'll be honest, I played five or so ranked games with Vi before I actually played her in normal games.
Meep Man4 votesCan we just slow down and realize that for nearly no reason, Shaco, an Assassin in a Tank Meta, is suddenly getting picked a decent bit? Congrats to the League player base for bring him back up a bit.
Now, what were we saying? Oh yeah, DONT FIRST TIME SHACO! That psycho may seem like freelo, but, oh my gosh, if you don't know how to properly play him and put the enemy team on tilt 90% of the time, don't play him.
Saianna1 votesHe's too outdated to be considered real threat assassin. His skills are waaaay too spread on AP & AD which makes him rather mediocre.
He can kill, but in most cases it feels undeserved, Ks like..
Darth Pixy Misa3 votesShaco seems straight forward to play, but is actually a champ with a high skill cap. It is not wise to use Shaco in ranked till you understand how he works in ganking, and team fights.
CubedJustice2 votesShaco in team fights: Be in a different lane
The Bíg Ticket3 votesStop playing Shaco at all if you are not insane and in need of psychological help.
Trash MammaI2 votesin need of psychological help.
That's like the majority of the league community considering how many people tell you to go kill yourself because you said no to giving them blue buff
The Bíg Ticket2 votesFair point.
DrNova3 votesSTOP FIRST TIMING EVERYONE IN RANKED. Or second time. Or 5th time Maybe even tenth time.
OblongOtter2 votesSo i can third and fourth time, but have to do a normal for the 5th? Got it.
Starcall Casey2 votesPretty much the goal is to help others believe that first timing anyone is bad and you should never do it in ranked. Ranked is a competitive queue and should be treated as such.
Daen2 votesI agree, though it seems odd to me that you mentioned Riven, one of the most mechanically demanding melee champions, as an easy one to pick up and play. She is not particularly strategically demanding, but without moderate understanding of animation cancellation and her combat flow she's pretty weak.
Shaco, however, is a whole 'nother can of worms. He's one of the only strategically demanding champions in the game; Shaco requires pretty detailed knowledge of his jungle paths and role, neither of which holds much similarity to other champions.
Trash MammaI1 votesI've seen Rivens roflstomp by doing nothing but button mashing. They don't even AA between their Q uses. They hardly ever time their Q's they legit just press QQQ W E away repeatedly. Then it's just flat out game over cause someone thought a person with an ad scaling shield needed an ad steroid..
Daen2 votesI've seen Rivens roflstomp by doing nothing but button mashing.
Then they are against sub-par opponents. A huge portion of her damage relies on chaining her abilities together and weaving autoattacks between them, she's a pretty weak champion if the player ignores all of those intricacies.
Trash MammaI1 votesWell, when you have an AoE knockup a stun and a massive shield it's kinda hard to lose trades either way. My first time with Riven I nearly died of laughter from how easy it is to legit faceroll with her. I did nothing but button mash cause I knew I could get away with stupid things being crazy mobile/tanky(shield)
DarthSpectrum2 votesRiven is at least 4 times harder than Shaco. Sure, she is strong and has an overbearing kit, but it is precisely the nature of her kit that will throw new players off. Learning how to animation cancel and block attacks at the last moment with E is unique to Riven. People who just picked her up will not know these skills.
Shaco on the other hand only have some relatively simple things to keep in mind.
Everything else is the same as playing any other champion.
Also, League has a built in meter on how difficult it is to play a champion for the first time. If you think Riven is bad, try watching first time Yasuo, Rumble or Annivia. Their abilities can practically hurt themselves more than the enemy.
DrNova1 votesOr R click. Easier.
ScreamPaste1 votesFirst timing with Riven in ranked should be reportable, lol. First time Rivens are garbage. She's one of the most mechanically demanding champions in the entire game.
First timing Shaco is just as bad, though.
Rysophage1 votesI first timed braum wukong lissandra and did fine. I just have common sense and can read. And i have a general idea of how every champion works i dont need to be faker to do well.
MrSlowDie1 votesIs shaco a thing now? I haven't check league for a while, and back then it was hard to find shaco.
did he get a buff or something?
Trash MammaI1 votesThe new jungle made his early game sleeper op. You can find the enemy in their jungle with low hp so much it's crazy. He's still feast or famine but it's a lot easier to do things now. Except a lot of players I see don't even realize WHAT the new jungle buffed and still try season 2 crap
Minrog1 votesI am not sure regarding buffs, but he got played in the EU LCS Quarterfinals by Kikis from Unicorns of Love; game 4 against Gambit Gaming.
http://na.lolesports.com/vods/league/eu-lcs/2015/eu-lcs-spring-playoffs
Salidfingers1 votesI got to gold as shaco jungle.
Every other game people thought i was trolling when i selected him.
ABlueQuaker1 votesWhile I have at least SOME experience on every champion, I'll admit that there are some champions I don't feel comfortable playing in Ranked.
That said, some champions' kits are binary enough to get away with playing with little experience playing them. I mean, as rarely as I play them I've used the likes of Nasus and Udyr Top Lane in Ranked Solo Q purely because they make good split pushers if all else fails.
EDIT: As for Shaco himself, I see no reason to pick him at all. There are better counter junglers if you want to counter jungle, there are better assassins if you want to assassinate, and there are better split pushers if you want to split push. I really don't like Shaco because, while he does a lot of things, he does nothing consistently well.