Ever since The Great Turnback happened, RuneScape players have been looking for many ways to make a lot of cash very quickly. Player-killing was fine and all, but has one hell of an steep and expensive learning curve. Scamming worked for about 30 minutes on the first day back and that was about it, and anything else was too much bloody trouble for the lazy bastards. Eventually people managed to clock on to the ability to perform Gambling on RuneScape - the very height of become very rich very fast, or very poor even faster. However, there are many ways - most of them not a load of cop.
The Flower Game[]
This one was a simple design - bet upon a certain flower colour to appear with Mithril seeds and if you guessed right, you win. However it is always a trust trade - the vast, vast majority of hosts for the 'Flower Game' are scammers and will make a run for it the second you end up winning. Most of them are dead obvious anyway - no one is going to give you an Armadyl Godsword for a 1 in 9 chance at 500K a go. Nowadays dismissed as rubbish.
The Dice Game[]
Now one of the biggest gambling methods on RuneScape, this is similar to the Flower Game except you bet on the roll of a dice. Commonly this is done with the 1-100 dice, and the generally used methods varies from 55x2 to 60x2, where if the dice's roll adds up to the x2 amount, you get twice your bet back. There used to be a 100x3 - where on the incredibly rare occasion that the dice roll adds up to the absolute maximum, you recieve three times your winnings. Of course, this is not in effect in the vast majority of dice hosts, because they are shit scared of paying out three times of a massive bet providing the person is silly enough to bet that.
While once again, the vast majority of 11 year olds you see offering 'dicing' are just trying to steal pixel coins from you, there are many 'genuine' dice game clans that are designed to never scam, instead making their money from the unlucky and foolish, or in the case of a couple of the more well-known dice clans (such as Dragon Dyce and Smokin Mils Dicing, yes, that merch clan is trying to payback to the community) make money through commission fees, so if you bet 100M and won on a x2, you would recieve back 180 or 190M respectively. Arguably these were the first two massively successful dice clans, and now everyone is trying to jump on the board, with stupid names like Bum Hole Dice, etc.
Staking (Duel Arena)[]
Main article: Duel Arena
The grand daddy of all gambling methods...and easiest way to lose every single coin you ever had. While this existed during the 08-10 period of un-Free Trade, it was heavily restricted due to the trade limit and therefore only ever done for a piss around. Nowadays, and especially if you yomp over to W54, you will see staking is one big thing, with people staking hundreds of millions over the outcome of a slot machine. Dangerously addictive to weak-minded people, the vast majority of stakers end up with no money left (which is generally called 'being cleaned') while the extremely lucky (or cheaters) have billions of RuneScape gold, most of it they never use. Being cleaned doesn't just apply to the new stakers with a 120M bank, there have been times where billionaries got greedy and stupid then lost it all. All because the other person sneaked off the ability to fight with melee.