Cross-trading in Roblox is when a user trades something in-game, such as a pet or an item, for Robux, items in other games, or even real-life currency. It is against Robloxs Terms of Service, which means users can get terminated or banned, and it is also against the rules on some wikis, meaning users can get blocked. Cross-trading is not supported in some games, such as Royale High. However, there are some Discord servers that allow cross-trading, such as Roblox Cross Trading and Top Cross Trading. It is important to note that cross-trading is not allowed and can result in consequences, so it is recommended to avoid it.