Game System License
rpgitem
RPGs have variable players and duration.
Dungeons & Dragons 4th Edition System Reference Document
rpgitem
RPGs have variable players and duration.
d20 Modern System Reference Document
rpgitem
RPGs have variable players and duration.
System Reference Document
rpgitem
RPGs have variable players and duration.
Open Game License 1.0a
rpgitem
RPGs have variable players and duration.
The D20 System Trademark License
rpgitem
RPGs have variable players and duration.
d20 System Trademark Guide
rpgitem
RPGs have variable players and duration.
System Reference Document 5.1 (SRD5)
rpgitem
RPGs have variable players and duration.