One client per connection
Enforced automatically
Only one game client per connection is allowed. If a second account logs in from the same connection, the server closes both sessions, not just the one that just arrived.
Both going down is deliberate. If the first one survived, trying the second client would cost nothing and the rule would be optional.
Two computers in the same house are one connection. They share the same public address, so to the server they are the same thing. Whatever your machine shows you as «its» IP is not what the server sees.
If two people live in the same house
Write to us and we will register the exception. It is granted per account, not per address: addresses change on their own, and an IP-based exemption either expires by itself or —worse— gets inherited by a stranger when the provider reassigns it.
Moving items between your own accounts
Between characters on the same account, use the Kafra storage: it is shared among all of them and costs nothing.
Between different accounts, mail is the only way. Since you cannot have both online at once, a direct trade is impossible by definition.
Mail costs 2500 zeny per message with an attachment, plus 2% on any zeny you send. There is a cap of 100 messages a day and a weight limit per message. Whatever you send waits in the mailbox until you log in with the other account, so there is no rush and nothing gets lost.
Advice, not a rule: avoid asking another player to act as a bridge. It is the favour that most often ends in a lost item and an argument we cannot settle, because there is no way to tell forgetfulness from theft.
Shops do not count
An account left selling with @autotrade does not count as a second session: you can leave your shop up and keep playing on another account from the same connection.
The reason is simple. This rule exists so that nobody has two characters acting at once. A vendor does not move, farm, buff or fight, so it grants no advantage. What is not allowed is opening the second client to play.