The Doubling Money scam is a very common trust trade scam that involves the scammers taking players' hard-earned gold. In F2P worlds it is not uncommon to see several 'doublers' around the Grand Exchange. These types of scammers are also often found on Pay-to-Play worlds. A popular opinion is that in general, Free-to-Play players will be less experienced, and therefore not know as much about popular scams, while members are often richer and lose more money when they do get scammed.
The scammer will repeatedly say things like "Doubling money!" until a victim comes up to them and trade. The scammer will most likely asks the victim to "test" them and the victim will trade a small amount of money to the scammer. The scammer then trades them double the amount, claiming it's a glitch. The victim's greed then is manipulated and trades the scammer a larger amount of cash. The scammer then logs out, or attempts to increase the victim's greed even more.
Often these scammers are trolled by other members of the community. One common troll is to trade over a very small amount of money, then claiming that they gave the wrong amount of coins back. Sometimes players may stand around mocking the way that these scammers operate, except instead say 'Halving Money!'.
The scammer will usually log out when the victim offers large amounts, usually 100,000 coins or more.
Scammer: "Doubling money!"
The victim trades the scammer 1m.
Scammer trades Victim back 2m.
Victim (thoughts): "Woot! free money!"
Victim trades him 5m.
Scammer trades Victim back 10m.
Victim trades him 25m.
Scammer logs out.
Player 1 Says "Doubling money, 2 times per person max" repeatedly
Victim trades Player 1 100k, testing if Player 1 is scamming
Player 1 trades Victim back 200k
Victim thinks "OMG this guy is real, i only have one more trade left though so I should probably get the best deal i can"
Victim trades Player 1 Cashstack
Player 1 accepts
Player 1 logs out before Victim can report or taunts Victim
Victim trades the scammer 100K.
Scammer logs out.