Hello USJapan and welcome to Roll20! 翻訳コンピューターを使って日本語の勉強を始めました。 ゴールドオトサンと名付けられました Short answer: Yes you can customize everything like you asked, even on the Free account. Pat gave a good answer! Longer comments. You can develop your game gradually. In the beginning, Roll20 has an empty whiteboard, empty text pages, and Audio-Video-Text chat communication in real time. Anything that you can run as a game at your kitchen table, you can communicate in Roll20 using just the basic tools. It is not necessary to type your custom monster into Roll20, for the first game. You (the dungeon master) can say it verbally. "You are seeing a custom monster. The teeth are very big." The players roll some dice to hit the monster? You can write the Hit Points on your notepad at home. It is not necessary to begin Roll20 gaming with fully-programmed monsters in the database. You can run any monster, and be the dungeon master, verbally and using paper. Roll20 will assist the communication, maps, dice, chat, even in the most basic empty starting form. Advanced Roll20: Yes, you can configure Roll20 to enter your custom monsters. It can have a character sheet, stats, attributes, macros, pre-programmed dice rolls, abilities, hit points, picture, language, everything. However this takes time & knowledge to set up. However the important message is, you can play a basic version of Roll20 as your first stepping stone towards doing Advanced later. Advice: The best place to begin is "Create Game" button on Free account. Invite your friends. Begin to communicate. Test the features. Then decide which features to type and automate.