http://eu.finalfantasyxiv.com/lodestone/playguide/contentsguide/goldsaucerThe Gold Saucer is Eorzea's premier casino, run by Godbert Manderville. There, you can take part in a variety of attractions to earn Gold Saucer currency (MGP) to spend on mounts, minions, dances, hairstyles & glamour items unobtainable anywhere else. Plus the attractions are pretty good fun, once you learn how they work!
To access the Gold Saucer, you need to finish the quest "It Could Happen to You", issued by the Well-heeled Youth in Ul'dah - Steps of Nald (9-9). He will give it to you after you finish any of "The Gridanian Envoy", "The Lominsan Envoy" or "The Ul'dahn Envoy" main quests.
Once inside, you can buy a starter stack of MGP for gil from the main counter.
Claiming prizes:After accumulating sufficient MGP, players can speak with the Gold Saucer Attendant at Entrance Square in the Manderville Gold Saucer (X:5.1 Y:6.7) to exchange their MGP for myriad prizes.
The Modern Aesthetics saleswoman, at Entrance Square (X:5.4 Y:6.5), offers hair catalogues which include the hairstyle design contest winners in exchange for MGP.
The Minion Trader, at Minion Square (X:7.7 Y:7.0), offers minions in exchange for gil and MGP.
Unwanted cards in your inventory, such as doubles of those already registered to your card list, can be sold for MGP to the Triple Triad Trader at Card Square (X:4.1 Y:7.4) or the Triple Triad Trader at the main counter in the Manderville Gold Saucer (X:5.0 Y:6.4).
Main attractions:Weekly Cactpot:
Weekly lottery that could win you lots of MGP, or more likely a small profit on the ticket cost as a consolation prize. You can enter up to 3 times per week, and the draw is every Saturday at 8pm server time.
Mini Cactpot:
Daily scratchcard, of which you can buy 3 per day. Each scratchcard awards prizes based on the sum of the line you pick, up to a maximum of 10,000 MGP per card. You can scratch off 3 panels to give you an idea which line to go for. The best combination is 123, followed by 789. The mini cactpot resets at daily reset time (4pm server time).
Chocobo Racing:
https://www.reddit.com/r/ffxiv/comments/5tcin9/chocobo_racing_tips/https://www.reddit.com/r/ffxiv/comments/5tybea/1010_races_and_an_army_of_retired_chocobos_later/https://ffxivchocoboracing.wordpress.com/https://ffxiv.consolegameswiki.com/wiki/Chocobo_Racinghttp://finalfantasy.wikia.com/wiki/Chocobo_Racing_(Final_Fantasy_XIV)Triple Triad:
http://arrtripletriad.com/https://ffxiv.consolegameswiki.com/wiki/Triple_Triad_CardsLord of Verminion:
http://ffxiverminion.com/guidesSome advice from our lovely Yaya -
- if in doubt, use Kidragoras! Summon them all at one gate (for example A). Send them as soon as they spawn to the left stone. Then keep summoning more and sending them. After the first stone is broken take the whole bunch to the middle and after that to the right one.
- for Stage 19, send a army of Yugiris there. They are amazing.
- in stage 20 (using Kidragoras), the best way is to work your way from left to right or right to left to shorten distances. If you start in the middle you are likely to loose. Focus on the arcana stones and avoid the enemy minions.
- stage 23 works the same way as 19 with all the Yugiris. It's much simpler than the guide implies.
GATEs:
Gold Saucer Active Time Events, or GATEs, are audience-participatory events staged within the halls of the Gold Saucer. GATEs in progress will be indicated with a gold icon on your map. To participate in an event after it has been announced, seek out and speak with the GATE client nearby.
GATEs at 15 minutes past each hour:
These 2 GATEs are always on the stage in the Event Square. To join, talk to the NPC at the very north of the room and they'll teleport you onto the stage. These GATEs can be retried by speaking to the GATE Client and paying the fee again, as long as you're still within the time limit. These GATEs will despawn at either 25 or 30 minutes past the hour - your duty list will tell you how long you have once you join.
Cliffhanger
Wonder Square or Round Square - GATE Client to speak to will be on the upper level.
This is a jumping puzzle - avoid the bombs and jump between ledges to rescue the baby chocobo at the top. If you get caught by a bomb you'll be blasted off the edge and will need to talk to the GATE Client again to restart. Note that bombs are close to exploding when they glow orange.
Vase Off
Round Square (6, 4) - GATE Client to speak to will be on the lower level.
The GATE Client will give you either 2 or 3 vases to be delivered to NPCs marked on your map. One of these is on the lower level of the Event Square under the stairs and 2 are on the upper level of the Wonder Square. The catch is that you need to avoid being spotted by the purple-uniformed NPCs roaming the Gold Saucer, and you can't jump off balconies. You can, however, use the water spouts to get up to the balconies.
There are no roaming NPCs in the passages connecting the Squares, but they're everywhere within the Squares themselves. You can run past the roaming NPCs when their backs are to you, and can run past them in the upper levels when they patrol away from you and there's room down the side of the balcony. You may need to wait for one to go up/down the stairs before you can pass.
Optimal route and NPC locations are as per my crappy Paint diagram here:

(sorry for the shaky lines!)
Skinchange We Can Believe In
Wonder Square - GATE Client to speak to will be on the upper level.
Look carefully at the NPC and find the identical NPC from amongst the potential imposters dotted around both levels of the Square. Things to look out for include colour/style of shoes, gloves, facial hair, patterns on weapons, etc. The differences can be really tiny, so be sure before you point the finger at one of the NPCs! I find it helps to take a screenshot and paste into Paint to refer to while examining the imposters.
GATEs at 45 minutes past each hour:
These 2 GATEs are always on the stage in the
Event Square. To join, talk to the NPC at the very north of the room
(8, 5) and they'll teleport you onto the stage. Bear in mind that you only have 2 minutes from when the GATE spawns to get to the NPC and join in.
The Time of My Life
The objective of this GATE is to successfully copy the emotes the NPCs will use. Once on the stage, you'll notice that your Hotbar 1 will be replaced with an emote hotbar, consisting of all the possible emotes the NPCs can use (e.g. bow, panic, laugh, pray, etc).
After a bit of preparation time, the stage with filled with 14 NPCs - 1 of each race and gender. You should find your corresponding NPC and stand in front of them, as this makes it much much easier to tell which emote they're using. Note that 10 NPCs will be on the stage, and 4 will be on the raised platform above it. You can still see those clearly if you move your camera.
The NPC's 'dance' will consist of 4 stages of 4 emotes each, and you'll get 20 seconds to perform the correct sequence once the NPC has finished each set. You can tell when to start emoting the sequence when the time appears in your duty list and the floor goes all disco. Don't worry if you get some wrong - you only need to copy 10 of the 16 correctly. You can see how many you've got correct and which stage you're on in your duty list.
Any Way the Wind Blows
Fun with Typhon! Once on the stage, you'll get a bit of time to find somewhere you like the look of while waiting for Typhon to get his lazy ass on-stage. Once he appears, he will attempt to snort you off the stage 5 times. You'll be rooted in place while Typhon is snorting, but can freely move position between snorts if you think somewhere else on-stage looks more lucky. This GATE is pure RNG and there's no baiting or safe spots, whatever anyone tells you.
If you complete this GATE successfully 10 times you get a fancy title telling the world you beat RNG! The real end-game, no matter what Kema tells you about fishing!
Mini-games:
Dotted around the Gold Saucer you'll find a selection of arcade-style machines that can be played for small rewards (except for one that's well worth using to farm MGP)
Monster Toss
Keep your eye on the basket, and make as many shots as possible before the buzzer sounds.
Crystal Tower Striker
Watch the gauge and bring down the hammer in a test of strength against this formidable high striker.
The Moogle's Paw
Keep your eye on the prize, and guide a sure-handed moogle to its goal.
Cuff-a-Cur
Keep your eye on the gauge and see how much of a punch you pack.
Out on a Limb
Best mini game MGP reward by far, so it's well worth learning to play!
This mini game is basically botany from 1.0. First you select the difficulty with the button - Cactuar is easiest (slowest), followed by Morbol, then Titan (fastest). Then you get show a segment of a tree, with a swinging hatchet.
The concept is that there's an item somewhere in that segment and you have to stop the hatchet on or near it to deplete the bar underneath it and 'find' the item. You can stop the axe anywhere in the segment by pressing the button.
The harder the difficulty you chose in the first part, the faster the hatchet will swing. The best way to do this one is to stop the hatchet 1/3 of the way in and see how close you are, then adjust accordingly. The game will tell you if the hit was a miss (no progress on the bar), good (1/6 of the bar), great (1/3 of the bar) or excellent (all of the bar in 1 hit).
Each time you 'find the item' you'll be given the chance to double up on your reward. You can keep doubling up within the minute you're given, but watch out for the time remaining - if the timer runs out you win nothing.
The game is much simpler than this makes it sound - just have a play around and you'll get into the swing of it (sorry).
The Finer Miner
Swing the pickaxe to locate the hidden ore. This mini game is basically mining from 1.0.
It's very similar to Out on a Limb, but instead of a segment, you will see a circle with an expanding/contracting circle. The rewards aren't anywhere near as good as Out on a Limb, though.