To clarify. Wizards of the Coast releases a simplified and smaller version of their rules that can be freely used by anyone. You can create software and adventures that reference this material without purchasing a license, or more accurately, using the freely available Open Gaming License. This rules document is called the SRD , for System Reference Document . Without an actual license, you cannot use anything that is not in the SRD, for example, most subclasses, feats, some monsters and spells, and all art. If you have not purchased a sourcebook (which Roll20 has negotiated a licensing deal for), you are limited to those things that are in the SRD. For example, to everyone's surprise, this also includes the mechanic of rolling for your basic ability scores. That method is not in the SRD, so the charactermancer requires you to use one of the other methods. This is also true of many character options, and is why the basic free monster selection on Roll20 contains no artwork for the tokens.