My group is starting up Legacy of Fire shortly, and one player is planning on a Paladin of Sarenrae. He saw the Strength of the Sun trait and pointed it out to me and we were wondering, what exactly does it apply to? Is it only going to be Cha skills and Concentration checks, or will he also get it to attacks while Smiting and to saves once he gets Divine Grace and so on?
Strength of the Sun
You take solace in the purifying light of the sun. During the day, you gain a +1 trait bonus on all Charisma-based checks.
The generally accepted definition of a Charisma-based check is a d20 roll in which the stat it is based on before any other modifiers (such as from other stats) is Charisma.
As stated above, a will save with Divine Grace is a Wisdom-based check with a bonus equal to your Charisma modifier. It's not a Charisma-based check.
There is an alternative interpretation that any d20 roll that includes Charisma is a Charisma-based check but that can get silly pretty quickly.
This query seems answered but I just wanted to chime in with a cool Strength of the Sun fact. Since concentration checks are based off of the spellcasting modifier of the caster, CHA-based casters snag the +1 on their Concentration checks. Could be useful if your buddy wants to do the pretty common Oracle multiclass on his Paladin.
Between this trait and the Seeker archetype for Sorcerers and Oracles you can get pretty dang good at casting while monsters are chewing on your heels.