Robust
Robust, initially a term to describe the GUI and combat system of SS13 has since grown into a philosophy with different schools of thought. While used often as a word to describe someone being bested in combat (e.g. "I sure robusted those scrubs last night, gosh am I awesome.") ultimately to be robust one must do more than simply master hand to hand, ranged and chemical combat within SS13, but rather take upon a play style which incorporates quick thinking, foresight, knowledge and an ethical code which is unique unto each player on their own.
Being robust is not just knowing how to smash your foes faces in with a toolbox without being killed yourself, being robust is helping, serving and protecting those who cannot do these things for themselves. In other words, Bane may have broken Batman's back, but even when he was broken, Batman was more robust.
Combat
The most basic levels of robustness require a degree of combat prowess. Not only does a robust individual know how to remove a dangerous crew member or other life form permanently from the station but also how to safely and non-harmfully incapacitate a crew member who does not deserve death. A robust individual is able to assess these situations and determine the appropriate action as well on their own.
Knowledge
A robust individual may be a jack of all trades, or an expert in but one specific aspect of SS13, but what makes them robust is knowing where their strengths lie. Learning new things is always a positive trait, but never when your knowledge you have is needed in an emergency, or when learning new skills and talents is potentially dangerous to other crew members. A robust individual knows how to get out of most situations without needing to destroy or hurt anyone, and if need be, restore anything they do destroy later.
Foresight
A robust individual can assess situations big and small and know how to prepare in the future, and then does that. Reports of hull breaches will cause a robust individual to ready an air supply, reports of the singularity escaping will cause a robust individual to carry a crowbar for powered down airlocks. Having knowledge of how to get out of a situation, or knowing how to defeat certain foes is no good if you are not prepared for it. However there is a fine line, a robust individual never needlessly prepares for situations. You will never see a robust crew member hoarding commonly used tools purely in case something happens. A robust individual knows what they need to acquire, and does so without destroying property or breaking Space Law unless the situation is dire enough to warrant it.
Ethical Code
The most subjective of this list. Each robust player adheres to a specific ethical code which is unique unto themselves and themselves alone. Certain situations will warrant each player a different reaction. Some may seek out to repair damage first, while others focus on healing the injured, between these two situations they are both robust, but different in the ethical code they follow. After mastering combat, knowledge and foresight a truly robust individual will meditate and consider what is important to them, and the station as a whole.
Ethical codes can go wrong however. A robust individual can master the three above laws yet have a selfish ethical code which does not benefit anyone but the one using it. These people are the dark ones, the griefers, the shitlords. A truly robust player does not seek out conflict with these individuals, but will often find themselves thrusted into it no matter what.
Expect to be the one to die.