Scams
In MapleStory there are players known as "scammers". These are the players who will try to leave a trade made with another player with the item they want, but they will not give the other player what they had agreed on. Scammers try to rip others off to benefit themselves. Below are some examples of scams:
Misreading Scam
Player1 is our scammer; Player2 is our random player.
Player1: Hey, I'll buy your sword for 50,000 mesos.
Player2: (Hmmm... that's 20,000 mesos more than it's worth!) Okay.
-In the trade-
Player1 places 5,000 mesos in the trade. (10 times less)
Player2 places his/her sword in the trade.
Player1 accepts the trade.
Player2 accepts the trade.
Player2 has now been scammed out of his/her sword. He/she has received much less mesos than he/she would have received if he/she would have sold it without being scammed. Player1 now has received a cheap item and can keep it or sell it for more than he/she paid (5,000 mesos).
Fame Scam
Player1: Trading fame!
Player2: I want to trade!
Player1: You up (my fame) first.
Player2 gives Player1 fame.
Player1 runs off or logs off without faming Player2.
-or in a worse case...-
Player1 defames Player2, who was not paying attention and by looking at the chat bar
thought that he was famed.
Most scams can only work if the person being scammed isn't paying attention. As long as the target is aware of what is going on and is cautious, they should be able to leave the trade without being scammed. Player2 shouldn't have to worry about scammers in games, but the reality is that they will always be around, games like Maplestory has no "scam protection".
As for the fame scam case, you are actually risking your fame when you trade fame, or sell/buy fame, because in Maplestory, there is no "legitimate" way to trade fame, and you just have to trust the other party. So technically speaking, the fame case is not scamming, although the two players have made a mutual agreement of faming each other.
Freebies
Players on other online games can also be scammed without even being on the game. In Maple sometimes people will create websites with promises of "free mesos/meso generator", "free items", or other freebies for the game in exchange for their account info and password. If the target is selfish enough to want to cheat at the game or isn't intelligent enough to realize that these websites are scams and the owners are trying to steal their accounts, they could be said to have deserved their losses.
Trust Game
Some person say that they will give you a item if you drop your items right in front of them and then they will reward with money then ask you to drop more. When you drop a item they want, they have this kind of thing where they like teleport over to your spot even if they don't have a skill teleport and loot them. Aftter taking them they would, log out, or transfer the items to their real character.
Drop Game
Another is the "Drop Game" to some, this game is to have fun. A person offer to play the game with you: and asks you to drop a equip/rare item, and tries to get it. Thats the point of the game. You're supposed to get your item fast enough.. next they will move far away then drop, for the advantage. If you can quickly pick up your items, then it's okay, but beware of wizards with the Teleport spell, who can cheat at this easily. Also, there are maplers who use Item Vacuum hack, a hack that can suck up all items dropped on the ground, and other maplers may be hiding in the shadows where you cant see them. Do not play these games.
Trade Trick
Some person tell you he/she will help you duplicate you money and/or items. They will tell you to press trade but don't press yes. Then they tell you to type something. DON'T BELIEVE IT!!! The word will have a Y in it and when you press it, it will automatically press yes. They other person just presses yes and gets your stuff for free. The other letter don't do anything.
Conclusion
Scams are against the rules. If somehow you are scammed, it is a reportable offense. When reporting, make sure you have proof, such as screenshots of chatlogs. However, there is no secure way to trade fame in Maple, opening it to abuse. If you drop your items, be prepared to lose them. Pay attention when trading and it shouldn't be a problem, but remember: Scams are against the ToS, and GMs (Gamemasters) can intervene because scamming is against the rules. For a list of common scams go to How NOT to be scammed