• Crafting Assembly: Crafters who catch a lucky break can benefit from a Critical Success during the Assembly phase of creating their item.
• Crafting Experimentation: During Experimentation, Traders can get a lucky break that will give their experiment a Critical Success.
• Combat and Faction: During combat, anyone fighting has a chance to be lucky which will earn them bonus Faction Points.
• Healing: All healing actions including the use of special abilities, healing others and even using stim-packs have the chance to receive a lucky break that will boost the effectiveness of the heal.
• Fencing: Another interesting chance for a lucky break is selling your goods to a Junk Dealer. Everyone has the opportunity for this lucky break which increases the item's "sell rate." A player can tell when they've been lucky because all of the prices of their goods will be considerably higher than usual.
• Stealing: Spies have an interesting luck ability. They can steal an item without any chance of getting caught.
• Theft Detection: Luck can also cut both ways in the course of stealing. Not only do spies get a chance for a "free steal," but everyone else gets a separate chance to catch the thief (as long as the spy doesn't get a "free steal"). While a spy is stealing, their target can get lucky by automatically detecting the spy.
• Experience: Last on our list of lucky breaks is experience. If you're really lucky, you can get a bonus to your experience point (XP) rewards while you're playing the game. It can happen at any time whether you are on the ground or in space, questing or crafting – as long as you're doing something that earns you XP.

Via Star Wars Galaxies