Adding enhancement to an existing magic item

[Boone]

This is a simple question...

I will use the sword example.

If I have +2 sword can add other magical enhancements to that sword? Ie. Flame burst, ect....

 

[CRGreathouse]

Yes. A +2 longsword can be made into a +2 flaming longsword. This costs the difference between the swords - 10,000 gp to have it done for you, or 5,000 gp and some XP to upgrade it yourself.

 

[dcollins]

See DMG p. 246, "Adding New Abilities".