We now come to the question of application. You now have -- or should, unless you've been reading these classes out of order in which case shame on you -- a working knowledge of how the Universe works according to modern scientists as well as the key ways in which Star Trek plays with them. Now, is that actually useful in STF? The answer is: Sort of.
The first thing to remember is that most STFers have NOT read this wonderful treatise on everything you ever wanted to know about physics but were afraid to ask. And unless you have an advanced degree yourself , chances are you are sitting there now with no idea how to apply all of this techno-babble in your daily RPing. (Or weekly for those of you in Fleet Two, or hourly for those on the Endevour.) Well guess what, that's not as big a problem as it seems.
There's a great deal of valid, relevant information not covered here, much of it more useful in your IC posting, in the TV shows themselves. And there's still more in the canon publications. More on those later.
So why are you still reading this? Here's why:
To role play in engineering takes 20% technical knowledge, 30% Star Trek technical knowledge, and 60% creativity. And being able to add is often useful. (Damnit!) Some people with extensive knowledge make bad engineering officers, and some of the best engineering officers simply prattle off terms without any clue how they work. Of course, the very best engineers know what they're talking about and can toss around terms that make sense. And you're here because you want to be the very best. Right?
Now then, some things to keep in mind when RPing in engineering:
Being a miracle worker may make for great humor and character development, but it is very easy to get carried away. Even more than security, the miracle worker engineer is the single most likely place to have "superhero" characters develop. Always watch yourself. If the framistan modulator is fused, consider it dead. If it's damaged, consider it repairable in an amount of time that will make it useful just barely in time to save everyone's life.
You can never have a system working too good. Well, that's not quite true. You can. If the ship's specs state that the ship is capable of warp 8.9, then it may be possible to squeeze 9.1 or 9.2 out of it for a few minutes, at the risk of the whole thing blowing up in your face (which is up to the GM to decide). But don't expect to "rig" the engines to pull 9.5 or 9.7. They can't do it. This also comes under the heading of don't abuse your power, or your power distribution systems.
The Chief Engineer especially but other engineers as well should make it his personal responsibility to know the ship forwards and backwards. If there are specs posted for a ship, read them several times and memorize them forwards and backwards. Have a bookmark for them for easy access. And follow them. The CE is normally the person to bring up the special perks of each class. Be sure that you know what they are, and use them appropriately. The CO and CE are the two people in the best position to help create a "personality" for the ship, even if it doesn't have on of those neato Nyetscape AI systems.
If something is broken but you don't know what, use a name that sounds reasonable that you heard them complaining about on the show. If the shields are damaged, the shield emitters could be off-line (read: repairable), they could be fused or destroyed (read: beyond all hope until they are suddenly and miraculously fixed at the start of the next mission), or they could be damaged (read: repairable but maybe not in time). If the phasers don't work, it could be the emitters -- the actual crystals that fire the beam -- it could be the generators which make the energy in the first place, it could be the conduits between them, or it could be something else. The EPS system is the 24th century equivalent of the electrical wiring, although it doesn't run on electricity. When in doubt, try and think what Geordi would yell at the comm system while things were exploding.
If you are the CE, then like any good Department Head, you should make sure your underlings have something to do. During off time this could be running a diagnostic or tweaking the system to be even better. Work with your junior officers, not over them. If everything is exploding and you're under attack from the Evil GM's Nameless Aliens, make sure that everyone is in charge of something. Tell some people to handle repairs while others work on finding the miracle weapon or weakness that saves the day. And make sure that you are in one of those groups.
Speaking of that miracle weapon, the same warning that goes for superheros goes for superweapons. One of the hardest fine lines you will have to walk as an engineer is the line between what you think you should be able to do and what you can do in the context of the RPG.
For those of you who are still trying to aust your CE and take his job, be sure to stand out as a solid RPer, not as a grandstander. One of the easiest traps to fall into is that of superhero or grandstander. Always keep an eye on yourself. Aside from character development and off-duty activity that is uniform to all departments, engineering junior officers should involve themselves in the workings of the ship. If you have no assignments from the CE or CO, interact with your fellow engineers (including NEs) and tweak systems. Often, however, your biggest challenge when things aren't happening will be interacting with other officers, not the machinery. Even engineers need to have lives.
Know your GM's style. Some GMs like to give engineering a hard time and make them do all the work. Others tend to ignore it. Figure out how your GM works and play into it. If nothing is happening make something happen. Not a core breach, but a fluctuation, or a misalignment. Force the GM to remember that you're there. If the GM seems to have a vendetta against engineering, do your best to keep up and try and steer problems to other departments, such as science.
As in any situation, the GM has the final say. You can appeal what the GM says to the FComm and GMDir, but assume that the GM is always right. Even if in reality what you are doing is perfectly legitimate, if the GM says you can't do it, you can't do it.
Remember what you learned in the first two lessons. They will come in handy when fixing major systems, as you can play around with them, as well as find new ways to do things that are the exact same thing but sound cooler, so they will work better for the next 10 minutes, just in time to save the ship.