Can you lose a level by crafting?

[Grayson01]

If you spend enough XP, by crafting or XP cost for a spell, that it would bring you bellow the level of XP needed to be say level 10 would you lose a level?

[Karnith]

You can't spend so much XP by crafting a magic item or by casting a spell with an XP cost that it would cause you to lose a level, though you can choose to spend XP rather than leveling up if you so desire. Per the SRD for item creation feats (http://www.d20srd.org/srd/feats.htm#itemCreationFeats):

Experience that the spellcaster would normally keep is expended when making a magic item. The XP cost equals 1/25 of the cost of the item in gold pieces. A character cannot spend so much XP on an item that he or she loses a level. However, upon gaining enough XP to attain a new level, he or she can immediately expend XP on creating an item rather than keeping the XP to advance a level. (Emphasis mine)

And for spell components (http://www.d20srd.org/srd/magicOverview/spellDescriptions.htm#components):

Some powerful spells entail an experience point cost to you. No spell can restore the XP lost in this manner. You cannot spend so much XP that you lose a level, so you cannot cast the spell unless you have enough XP to spare. However, you may, on gaining enough XP to attain a new level, use those XP for casting a spell rather than keeping them and advancing a level. The XP are treated just like a material component—expended when you cast the spell, whether or not the casting succeeds.(Emphasis mine)

[Grayson01]

Sure it can say you just turned level 17 and have only 15 xp points above the cap for level 17. You are a Psion and you cast Mind seed that has a 3000 XP cost. that would bring you down bellow XP value of level 17.

[Karnith]

Sure it can say you just turned level 17 and have only 15 xp points above the cap for level 17. You are a Psion and you cast Mind seed that has a 3000 XP cost. that would bring you down bellow XP value of level 17.
Well, there is a corresponding rule for psionic powers (see here (http://www.d20srd.org/srd/psionic/psionicPowersOverview.htm#xPCostXP)), so in that situation you simply couldn't manifest the power if you had already leveled up. You need to have enough spare XP to manifest the power (cast the spell, craft the item, etc.); if you don't, you can't. Per the SRD (http://www.d20srd.org/srd/psionic/psionicPowersOverview.htm#xPCostXP):

On the same line that the power point cost of a power is indicated, the power’s experience point cost, if any, is noted. Particularly powerful effects entail an experience point cost to you. No spell or power can restore XP lost in this manner. You cannot spend so much XP that you lose a level, so you cannot manifest a power with an XP cost unless you have enough XP to spare. However, you can, on gaining enough XP to attain a new level, use those XP for manifesting a power rather than keeping them and advancing a level. The XP are expended when you manifest the power, whether or not the manifestation succeeds.(Emphasis mine)

[Grayson01]

Okay that explains my question thank you :-)