Should a GM desire, restrictions can be placed upon how much extra damage is done against foes with unknown weaknesses.

For example, the PC's encounter a strange alien creature that has no reconizable head - only multiple tentacles radiating from a a multi-lobulated 8 meter diamatere spheroid body. Not sure where to aim, they just try to cause as much harm simply by pouring as much firepower into the thing as possible. Ruling that the PC's aren't aiming at anything specifically, the GM rules that only 2d10 extra damage from the skill check can be used, even if normally a successful roll would give more extra dice of damage. However, during the fight, the Environmentalist spends time observing the creature and notices that it happens to be extremely protective of one of its tentacles, and so yells for the entire team to aim there (makes a successful Science: Biology skill check with an 64). The GM rules that with a 64, the PC's can now do up to 6d10 extra dice of damage since he recognized that the unique tentacle is the sensory organ for the creature.

A similar case can be used for unfamiliar robots and the Robotics: Identification skill.