Line of Sight

A character can target an opponent that they see, which is to say, any opponent within their Line of Sight. Draw an imaginary line from any point in the attacker's Fighting Space to any point in the target's Fighting Space.

If the player who controls the attacking character can draw that line without touching a square that provides Total Cover (a wall, closed door, or similar barrier) or Total Concealment (thick smoke, total darkness, or anything else that prevents Visibility), that character has a Line of Sight to the target.

A line that nicks a corner or runs along a wall does not provide Line of Sight. Other characters and creatures, Low Objects, Difficult Terrain, and pits do not block Line of Sight.

Line of Effect

Line of Effect works just like Line of Sight, but it ignores squares that provide Total Concealment. For example, a character who is blind or in total darkness doesn't have Line of Sight to any target, but that character has Line of Effect to any target that doesn't have Total Cover.

Additional Sense Surroundings

Reference Book: Star Wars Saga Edition Jedi Academy Training Manual

See also: Power of the Force

Many Force Powers require that the target be both within line of sight and within a certain range. The Sense Surroundings application of the Use the Force skill can be used to perceive targets despite the presence of Cover such as walls and doors or Concealment such as fog and smoke.

By the strictest interpretation of the rules, using Sense Surroundings to ignore penalties to Perception checks does not grant Line of Sight; it merely allows one to perceive the target (just as hearing someone coming around the corner doesn't grant Line of Sight.)

However, in some situations a Gamemaster may wish to allow a character to use Sense Surroundings to gain Line of Sight. If a character has the Improved Sense Surroundings Force Technique, the Gamemaster can allow a character that has perceived a target to also have Line of Sight to that target, provided that the character used the Sense Surroundings application of the Use the Force skill earlier in the character's turn.