This article defines server rules regulating item duplication. They are based on pre-Zucchini rules as well as consensus among a small number of members who were active in Discord at the time of discussion, and as such are subject to change by future discussion or vote.
These rules only apply to general-purpose item dupes, i.e. methods of duplication that can duplicate any type of obtainable item. Specific item dupes such as rail dupes or gravity dupes are unrestricted.
All usage of general-purpose item dupes is forbidden inside Renascence settlements until that settlement has slain an Ender dragon.
Other than that, whether or not a given item may be duplicated is determined by the following lists. An item on the whitelist may be duplicated, an item on the blacklist may not, and any item appearing on neither list is yet to be discussed. An established reason for putting an item on the whitelist is that collecting large quantities of it would otherwise require generating an unreasonable amount of terrain.