Re: A 958
Quote Originally Posted by mattie_p View Post
I know that Curmudgeon is no more authoritative in any real sense than either of us, but perhaps he would care to weigh in on this?
The Player's Handbook establishes that by default when you attack unarmed you provoke an attack of opportunity. The Improved Unarmed Strike feat and having your body charged with a touch attack spell provide overrides for this such that you are considered armed when making unarmed attacks. From PH pages 137 and 139:
Remember that even actions that normally provoke attacks of opportunity may have exceptions to this rule. For instance, a character with the Improved Unarmed Strike feat doesn’t incur an attack of opportunity for making an unarmed attack.
“Armed” Unarmed Attacks: Sometimes a character’s or creature’s unarmed attack counts as an armed attack. A monk, a character with the Improved Unarmed Strike feat (page 96), a spellcaster delivering a touch attack spell, and a creature with claws, fangs, and similar natural physical weapons all count as being armed.
In the "grope about to find an invisible creature" rules in the DMG Glossary there is no explicit exception to the usual rules for attacking unarmed. Therefore those attacks will provoke AoOs if the groping character does not have Improved Unarmed Strike, a touch attack spell charge in their body, or some other means of being considered "armed".

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The SRD conflates the Player's Handbook Glossary definition of invisible (pages 309-310) and the Dungeon Master's Guide Glossary treatment of invisibility (pages 295-296). However, the original source locations do matter here in terms of adjudicating disagreements.
Errata Rule: Primary Sources

When you find a disagreement between two D&D® rules sources, unless an official errata file says otherwise, the primary source is correct. One example of a primary/secondary source is text taking precedence over a table entry. An individual spell description takes precedence when the short description in the beginning of the spells chapter disagrees.

Another example of primary vs. secondary sources involves book and topic precedence. The Player's Handbook, for example, gives all the rules for playing the game, for playing PC races, and for using base class descriptions. If you find something on one of those topics from the Dungeon Master's Guide or the Monster Manual that disagrees with the Player's Handbook, you should assume the Player's Handbook is the primary source. The Dungeon Master's Guide is the primary source for topics such as magic item descriptions, special material construction rules, and so on. The Monster Manual is the primary source for monster descriptions, templates, and supernatural, extraordinary, and spell-like abilities.
Dealing with invisible opponents is a part of rules for playing the game. The Dungeon Master's Guide is where the "grope about to find an invisible creature" rules are. The DMG can supplement those PH rules, but it can't override them, or establish a conflicting default.