In many places I see referenced a "+1 rule" for characters legal in Adventurer's League play. What does this mean?
Version 1.1 Player's Guides
The “+1 rule” is shorthand for the restriction on being able to use the Player's Handbook plus one extra source to build your characters for the Forgotten Realms campaign.
WoTC has two different campaigns that utilize different limitations (currently v1.1).
- Forgotten Realms maintains the "+1" rule (see below)
- Eberron does not and includes additional resources and limitations.
Forgotten Realms (Waterdeep/Dragon Heist)
From page 2 of the 9.2 version of the Adventurer's League Player Guide (ALPG).
Forgotten Realms characters can choose race and class options from the Player’s Handbook and one other resource—a rule called “PHB+1.” Additional resources include the following products:
- Elemental Evil Player's Companion (EEPC)
- Sword Coast Adventurer's Guide (SCAG)
- Volo's Guide to Monsters (VGM)
- Xanathar's Guide to everything (XGE) [includes Tortle package]
- Mordenkainen's Tome of Foes (ToF) [Chapters 1-5 only]
- Locathah Rising (LR)
Additionally, when selecting an additional source, the following variant or optional rules are available when you create your character:
- Variant Human Traits (PHB)
- Half-elf and Tiefling Variants (SCAG/ToF)
- Option: Human Languages (SCAG) [This option isn't subject to PHB+1]
- Blessing of Corellon (ToF) [This option isn't subject to PHB+1]
NOTE: Races with flight at 1st level, and options from any resource other than those listed above aren’t available without specific campaign documentation (i.e., certs, etc.).
Eberron (There is no +1 rule per the ALPG linked above.)
From the 1.3 version of the Eberron Campaign Player's Guide (December 2019), which accompanied the Oracle of War campaign:
Oracle of War characters can choose race and class options from [see below] only (unless you possess campaign documentation providing additional options). You may select the Variant Human Traits option from the Player’s Handbook.
- Player's Handbook (PHB)
- Xanathar’s Guide to Everything (XGE)
- Eberron: Rising from the Last War (ERftLW)
The previous guidelines used for the Embers of the Last War campaign, released before the publication of ERftLW, substituted the below sources for that book and did not allow any exceptions for use of other material:
- Wayfinder's Guide to Eberron
- Volo’s Guide to Monsters (Bugbears, goblins, and hobgoblins only) (VGM)