Two People using the Trading System.
Trading is a special action where two Growtopians exchange items through a systematic method. Trading allows each person to buy or sell items, and it's safer than dropping them. but as good as it sounds it is not perfect. because some scammers "scam trade".
How to Trade
There are two ways to start a trade:
1) Use your Wrench and press the Wrench icon to the right the player's username. A menu will appear with 'Trade' and 'Add as Friend'. Press 'Trade'.
2) Type /trade [the player's username].
Note that you can trade only with people in the same world.
Limitations
Scam Trading
While the trade system is ultimately safer than the drop trade system, there are still flaws in the development.
For example, once two people (victim and scammer) get a perfect deal (59 High Tech Blocks for 11 World Locks), the scammer would immediately switch the World Locks to something else. This works because the victim tends to focus only on accepting the trade, to get this thing over with. The victim then accepts the trade and gets scammed.
This scam is easy to avoid thanks to a feature in which you can confirm the trade after both players accept. Pay attention to the trade before accepting to lower the chance for a scam.
Item Limit
The Trade System has a limit to only four items each player, so a person who wants to sell item packs has to either a) receive the World Locks first (and possibly kick the other person) b) sell them in packets (which suffers from disconnects and impatient traders) or to an extent, c) perform drop trade.