If I put an Incendiary Rune in a book then someone reads it, will the Incendiary Rune also set fire to the book?
If I put an Incendiary Rune in a book then someone reads it, will the Incendiary Rune also set fire to the book?
Yes. Incendiary runes works as explosive runes exept for the listed changes. Explosive runes state in the spell:
The object on which the explosive runes were written also takes full damage (no saving throw).
That would mean the same applies to Incendiary Runes since an exception to that is not listed in the spell.
On a related note, can I use suggestion to get someone to read said rune?
On a related note, can I use suggestion to get someone to read said rune?
Ask your GM. Suggestion, Charm and so forth are always weird to handle and the only real answer in the end for such things is ask your GM.
As for my OPINION, if you handle/RP it correctly, Suggestion would certainly be a valid means to get another character to read a letter.
Example: You have a letter with the ' XXX Runes' spell on it. You cast suggestion on the victim and say: "Can you do me a favor and read this out loud for me? It is a letter from my fiance and the last time I saw them we had a huge fight and I can't being myself to read it in case it is bad news."
That would be a perfectly valid suggestion. It is reasonable, and the target should have 0 reason to suspect the letter is a bomb, assuming they have not had reason to suspect you before.
But I think you get the idea.