Cross-Class
From HGWiki
Cross-class skills are skills that are not suggested for your class.
Putting skill points into these skills will cost you double skill points.
You can only put a maximum of 1 point per two levels into a cross-class skill. Except for level one where you can take 2 points, from then on the one point per two levels applies.
Examples Of Use
Classes such as shifters may find themselves wanting to put points into open lock and disable trap, this is because of their ability to shift into a "Kobold Commando" once they obtain the feat "Human Shape". The kobold commando can only open locks and disable traps if the shifter puts at least 1 point into each of these skills.
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