What does Force Light Do?
No points: You can't do it. This is a Rare, Mentored ability - one which requires a particular and deliberate fostering of dedication to Balance, the Light Side of the Force, and an utter rejection of the Dark Side and its corruptive influence. It must be fostered through training and taught to you by either a living teacher who knows it or through a Holocron of a noted practitioner - such as that of Arca Jeth.
1 Point: You have learned to manifest Light through the Force. Force Light is one of the few applications of the Force that can be seen and felt even by non-sensitive beings, able to present itself as a literal nimbus of visible light from the wielder. To do so takes concentration, and it drains your stamina quickly to do anything more than create a small aura of Light around yourself. At this level, you are unable to project Light as an offensive measure, but you can use it to entirely or partially protect yourself and others in a small area around yourself from Dark Side influences and abilities - though sufficiently strong manifestations of the Dark (such as through equal or higher Expertise levels, or DM plot occurrences) could overwhelm this protection. For example, the ambient taint in a corrupted area might not be of much concern to begin with, but with Light 1 you could safely ignore it entirely and enter more deeply corrupted locations such as Sith Tombs or Ritual Sites. An active threat, such as a Sith Ghost in such a place or a Dark Side wielder assaulting you with Dark powers might be a challenge to resist.
2 Points: You are able to protect yourself and others to a greater degree in a moderate area around yourself, and you are able to project Light outwards with intent. You can use applications of Light as an impromptu and imperfect alternative to Purification in a pinch. You can purge Darkness from tainted objects (fragile things may break), or lingering corruptive energies in an area - you might also be able to weaken the lingering effects of tainted wounds, physically or through the Force, but to try and purge them entirely this way would be draining to you and very painful to the subject with the possibility of lingering detrimental effects. You can also now attempt to use Light against opponents. Entities fully of the Dark Side, such as Sith Ghosts or Sithspawn, are most vulnerable to this and could be exorcised or destroyed (with enough repetition or weakening first), but living wielders of the Dark Side (I.E. Sith, other PC's) will at best be lightly harmed or inconvenienced by it - brief blinding or weakening of their Dark powers is possible. You cannot use Light protectively and offensively at the same time.
3 Points: You have become quite skilled with Light. Your ability to protect yourself and others is strong, and you can maintain such a simple application without much strain for an extended period - you are nearly impervious to ambient corruption this way, and attacks through the Dark Side towards you will have a hard time finding purchase. You can fairly reliably apply Light to cleanse the Dark Side from a location, structure, or objects in a pinch, and are proficient at countering creatures born of its twisted sorcery. Powerful artifacts or the ghosts of Sith Lords would still take quite a lot of effort to overcome.
3☆ (Mastery): You are among the true Masters of Light. Ambient corruption cannot touch you or those you protect unless it is truly extreme, dark side entities may be reluctant to even approach you, and you can cleanse large areas of latent darkness. Your ability is very reliable - but overuse will still drain your stamina and may knock you out or harm you still.