Do I need a client to play gb?
If you’re going to play seriously, then the answer is yes. Theoretically, one could get by using only telnet, but only the client will process maps correctly and enable you to encrypt your conversations, which is a convenient way to communicate at no cost without being overheard on the game. Additionally the newest GB+ server can optionally require CHAP (Challenge Handshake Authentication Protocol) authentication. If the GB server you connect to requires this then you will require a client. Right now, only the latest gbII (2.6.0) supports CHAP authentication.