Deflector screens

[Starbeard]

Here's what the '67 Star Trek Writer's Guide has written about deflector screens:

DEFLECTORS
The primary "defensive shield" of the U.S.S. Enterprise. It is, in effect, an invisible force barrier around the Enterprise which protects the vessel from anything but the most sophisticated and powerful weapons. It is
 automatically activated by the ship's sensors when an unknown danger approaches. Note: The ship's Transporter cannot be used while the deflector screen is operating. If the vessel should be under attack, the power of the deflector shield can be considerably increased, but at
 a commensurate loss in ship's power and at maximum shielding can only be maintained for a limited time. The ship also has "navigational deflector beams" which, guided by "navigational scanners", sweep out far ahead
 of the vessel's path through space, deflecting from the ship's course meteoroids, asteroids, or space debris and ether objects which would cause damage should the vessel strike them at this enormous speed. These are all fully automated, operated by the vessel's computers.

It's pretty straight forward, and really the only parts of the description that have changed over the years are:
1) since at least the Motion Pictures, writers have tended to force the captain to control the screen, instead of the automated computer ('shields up!')
2) since TNG at the latest (and possibly much earlier?), deflectors have had discrete facings ('starboard shields are down!')

Are there any instances of either of these ideas in use before The Motion Picture in '79? The Writer's Guide itself has other descriptions that were changed pretty quickly (phasers being described as what would soon become photon torpedoes), so it's entirely possible that there are TOS episodes that give a precedent for these.


I'm particularly interested in where the concept of screen facings originated, sine it's used in just about every Star Trek game I can think of since the '70s (maybe not the Battle Manual, I can't remember; but certainly in at least some of the spinoffs of Super Star Trek, and Star Fleet Battles). If it doesn't come from TOS, it might show up in TAS, or perhaps comics or novels. I didn't see anything about it in the Technical Manual.

[blackbat242]

The idea of specific parts of the shields/deflectors being disabled, or needing reinforcement, comes from some of the first season of The Original Series episodes, and is continually used throughout TOS.

And from near the start of TOS Kirk would order "shields up" or "raise shields"/"lower shields" - with the ship being damaged if attacked without the shields having been specifically raised (again, in several TOS episodes).

The first depicted use of shields by a starship was in the Star Trek episode "Arena", in which the USS Enterprise raises its shields after being attacked by an alien warship.

Note that the shields were not "automatically activated by the ship's sensors", but had to be manually raised.

[Starbeard]

I did a text search of 'shield', 'screen' and 'deflector' in the scripts of seasons 1 and 2, and what I found surprised me. From what I can tell, automated deflectors only showed up in season 2 (The Immunity Syndrome and The Ultimate Computer). This gives me the impression that the idea of automated deflectors was started in the Writer's Guide itself, which was between seasons.

Also, screen facings shows up in the season 2 episode The Ultimate Computer. Spock reports phaser hits on 'port deflector four' and/or 'deflector screen four' (I'm assuming they're the same, but it could've been intended to suggest that each side of the ship has multiple screens).

I haven't had time to search through season 3 or TAS yet. As a side note, the Star Trek Compendium (1976) entry for deflectors basically repeats the Writer's Guide information (and so assumes they're automatically turned on), then lists a number of various characteristics and limitations drawn from different episodes, but doesn't mention that they have discrete facings.

[Starbeard]

Here are the script passages from the first & second season where deflectors get mentioned:

FIRST SEASON

3. The Corbomite Maneuver (Jerry Sohl)
SULU: Sir, contact with an object. It's moving toward us. No visual contact yet.
SPOCK: Deflectors, full intensity

4. Mudd’s Women (Stephen Kandel & Gene Roddenberry)
SPOCK: Approaching an asteroid belt, Captain. Schiller rating three five.
KIRK: Deflectors on, Mister Farrell.
…
FARRELL: We're clearing the asteroid belt now, Captain.
KIRK: Deflector screen down, Mister Farrell. Save the power.

21. Tomorrow is Yesterday (D.C. Fontana)
SPOCK: We've achieved a stable orbit out of Earth's atmosphere. Our deflectors are operative, enough to prevent our being picked up again as a UFO. And Mister Scott wishes to speak to you about the engines.

22. The Return of the Archons (Boris Sobelman & Gene Roddenberry)
SCOTT: Captain, we're under attack. There are heat beams of some kind coming up from the planet surface.
KIRK [OC]: Status report.
SCOTT: Our shields are holding, but they're taking all our power.
SCOTT [OC]: If we try to warp out or move on impulse, we'll lose our shields and burn up like a cinder.
KIRK: Orbit condition.
SCOTT: Checking. We're going down, Captain. Unless we can get those beams off us so we can use our engines, we're due to hit atmosphere in less than twelve hours.
KIRK: Keep your shield up. Do everything you can to maintain orbit. We'll try and locate the source of the beam and stop it here.

23. A Taste of Armageddon (Robert Hamner & Gene L. Coon)
FOX: I have my orders, Captain, and now you have yours. You will proceed on course. Achieve orbit status and just leave the rest to me. You're well aware that my mission gives me the power of command. I now exercise it. You will proceed on course. That's a direct order.
(He leaves.)
SPOCK: In view of code seven-ten, Captain, may I suggest
KIRK: Yes, Mister Spock. This is the Captain. Condition Yellow Alert. Phaser crews stand by. Deflector shields up. We're going in. Peacefully, I hope. But peacefully or not, we're going in.
…
Ship's log, stardate 3193.0. Chief Engineer Scott recording. The Captain and First Officer are overdue and missing on the surface of Eminiar Seven. I have taken standard precautionary measures while we continue our attempts to locate them.
DEPAUL: All stations reporting. Deflector screens rigged at full power. Phaser crews ready. Sensors reading zero. Correction. Mister Scott.
…
KIRK: Final sensor readings?
SPOCK: No hostility directed toward us. No apparent notice taken of us at all, which seems strange. They did scan us when we assumed orbit. Obviously, they know we're here.
KIRK: Ship's defences?
SPOCK: Screens down, but all defensive details on general alert status, Captain.

24. Space Seed (Gene L. Coon & Carey WIlber)
KIRK: Then it's a derelict, its signal left on automatic.
SPOCK: Or an old Earth ship being used by aliens.
KIRK: Weapons status.
WEAPONS [OC]: Deflector shields on maximum. Phasers manned, sir.

27. Errand of Mercy (Gene L. Coon)
SULU: Captain, the automatic deflector screen just popped on. Body approaching.
KIRK: Configuration, Mister Sulu.
(Everyone is thrown about as the Enterprise is hit by multiple weapons fire.)
…
UHURA: Captain. Unit XY-75847 report a fleet of Klingon ships in their sector, sir.
KIRK: What bearing?
UHURA: Unable to ascertain, sir.
KIRK: Mister Sulu, have the phaser crews stand by their positions. Full power deflector screens.
…
SULU: Captain, a large number of Klingon vessels have just arrived.
SULU: They're opening fire.
KIRK [OC]: Positive identification?
SULU: Yes, sir. My screens are up. I can't drop them to beam you aboard.

SECOND SEASON

33. Who Mourns for Adonais? (Gilbert Ralston)
(Enterprise shudders under his anger. There is no longer a hand holding the ship.)
SULU: All phaser banks, maintain firing rate!
SPOCK: More power to the shields.

35. The Doomsday Machine (Norman Spinrad)
SCOTT: Captain, Washburn has our report.
KIRK: Go.
WASHBURN: We made a complete check on structural and control damage, sir. As far as we can tell, something crashed through the deflectors and knocked out the generators. Somehow the antimatter in the warp drive pods has been deactivated.
KIRK: Deactivated? Scotty, could some kind of general energy dampening field do that, and would the same type of thing account for the heavy subspace interference?
…
KIRK: All right. Lower your deflector screens Long enough to beam us aboard.
…
SPOCK: I am aware of the Rigel system's population, Commodore, but we are only one ship. Our deflector shields are strained, our subspace transmitter is useless. Logically, our primary duty is to survive in order to warn Starfleet Command.
…
DECKER: Mister Spock knows his duty under regulations, Doctor. Do you? (McCoy leaves) Hard about, helmsman. Course thirty two degrees, mark ten. Deflectors at full power. Ready on main phaser banks.
…
SPOCK: Deflector shields at full power. They can't take much more of this.
DECKER: Helmsman, hold your course. Stand by all phaser banks.
SULU: Aye, aye, sir.
(The planet killer fires at them.)
SPOCK: Deflectors holding, but weakening. We must retreat, Commodore. The energy drain
DECKER: I'm in command here, Mister Spock. Maintain your course, helmsman. Get us in closer.
…
(Another blast from the machine.)
SPOCK; Sir, deflector shields are gone.
…
DECKER: Mister Spock, status report.
SPOCK: Warp drive and deflectors will be out for a solar day. Repairs proceeding on transporter and communications.
SULU: It's closing with us again, sir.
…
SPOCK: Warp drive out. Deflector shields down. Transporter under repair. We are on emergency impulse power.
…
SCOTT: I've hooked in ship's communication. The best I can give you on impulse is one third power. The shields are up but they won't last long.

37. The Changeling (John Meredyth Lucas)
SULU: Captain, shields just snapped on. Something heading in at multiwarp speeds.
KIRK: Evasive manoeuvres, Mister Sulu.
SPOCK: An extremely powerful bolt of energy, Captain.
KIRK: Full power to the shields, Mister Scott.
SCOTT: Giving them all we got.
KIRK: All hands, Red Alert. Phaser banks stand by. Photon torpedoes to Condition Red, Condition Red.
(The viewscreen fills with a ball of bright light.)
SULU: It's going to hit.
(Everyone gets thrown around a lot, and the lights go out for a short while.)
SCOTT: Shields still holding, sir.
KIRK: Good.
SPOCK: Temporarily, Captain. Our shields absorbed energy equivalent to ninety of our photon torpedoes.
KIRK: Ninety?
SPOCK: I may add, the energy used repulsing this first attack reduced our shielding power twenty percent.
UHURA: First attack, sir?
KIRK: I think we can expect others, Lieutenant.
SPOCK: We can resist three more such attacks. The fourth will shatter our shields completely.
KIRK: Mister Spock, pinpoint the source. Mister Sulu, evasive manoeuvres.
SULU: Aye, sir.
KIRK: Lieutenant, contact Starfleet Command. Patch in my log. Tell them what has happened. Tell them the entire Malurian race seems to have been destroyed by an unknown agency, and that we are under attack by an unidentified force.
(Another ball of light is on the viewscreen)
KIRK: Helmsmen, I said evasive manoeuvres.
SULU: We're losing power, sir.
KIRK: Scotty?
SCOTT: I'm having to divert the warp engine power into the shields, sir, if you want the protection.
KIRK: Mister Spock, speed of those bolts.
SPOCK: Approximately warp fifteen, Captain.
…
KIRK: That's our target, Mister Sulu. Prepare photon torpedo.
(The third bolt hits)
SCOTT: Shields still holding, sir, but the drain on the engines is reaching the critical point. Ach, we lost warp manoeuvreing power. Switching to impulse.
…SULU: Sir, they've fired another.
KIRK: Can we take it, Mister Scott?
SCOTT: That's problematical, sir.
(It hits.)
SPOCK: Captain, shields are down. We cannot survive another hit.
…
(Nomad’s ‘protective screen’ ≠ deflector screen?)
KIRK: Sensor readings, Mister Spock.
SPOCK: Negative, Captain. It has a protective screen. I cannot get through.
MCCOY: What do we do now, go up and knock?
…
SPOCK: An almost human stubbornness, Captain. I have been unable to convince Nomad to lower its screens for analysis. Without its co-operation, I can do nothing.
KIRK: Nomad, you will allow Mister Spock to probe your memory banks and structure.
NOMAD: Mister Spock is also one of your biological units, Creator?
KIRK: Yes.
NOMAD: This unit is different. It is well-ordered.
KIRK: Follow your instructions, Nomad.
NOMAD: My screens are down.
…
(They leave. Nomad flies through the forcefield. The two guards fire their phasers at it but it's screens are back up. Nomad zaps them into oblivion.)

40. The Deadly Years (David P. Harmon)
UHURA: Sir, I've tried all known hailing frequencies. They simply ignore us.
STOCKER: Opinion, Mister Sulu.
SULU: They know they have us. They know our shields will give out.
STOCKER: Well then, we have no alternative but to surrender.
CHEKOV: Sir, the Romulans do not take captives.
…
KIRK: Message. From Enterprise to Starfleet Command this sector. Have inadvertently encroached upon Romulan Neutral Zone. Surrounded and under heavy Romulan attack. Escape impossible, shields failing. Will implement destruct order using corbomite device recently installed. Since this will result in the destruction of the Enterprise and all matter in a two hundred thousand kilometre diameter and establish a corresponding dead zone, all Federation ships will avoid this area for the next four solar years. Explosion will take place in one minute. Kirk, commanding Enterprise, out. Mister Sulu, course one eight eight degrees, mark fourteen. Speed, warp factor eight. Stand by.

44. Journey to Babel (D.C. Fontana)
CHEKOV: Captain, the alien ship has changed course and speed. Moving directly toward us at warp eight.
KIRK: Bring the prisoner to the bridge. Deflectors on. Red Alert. Phasers stand by to fire on my order.
CHEKOV: Aye, sir. Shields on. Phasers manned and ready, sir.
…
CHEKOV: Number four shield has buckled, sir.
KIRK: Auxiliary power.
CHEKOV: Switching over. Shields firming up. Number four is still weak, sir. If they hit us there again, it'll go altogether.
(Sickbay gets its power back.)
(Thelev is brought to the Bridge.)
KIRK: Your friends out there are good. They'll have to destroy this ship to win.
THELEV: That was intended from the beginning, Captain.
KIRK: You're not Andorian. Who are you?
UHURA: Damage reports coming in, Captain. Every deck.
KIRK: Damage control procedures, all decks. That ship out there has phasers. At least our weapons are alike.
CHEKOV: Number two shield is gone.
KIRK: Engineering, this is the Captain. Cut power on port side except for phaser banks. At my signal, cut starboard power. Kirk out. Who are you?

47. Obsession (Art Wallace)
CHEKOV: The creature is slowing. It's down to warp two.
…
KIRK: Fire photon torpedoes.
(The ship is rocked by the blasts at such close quarters.)
UHURA: There. It's coming, sir.
KIRK: Deflectors up.
CHEKOV: Deflectors up, sir.
SPOCK: The deflectors will not stop it, Captain.
SCOTT: That's impossible.
SPOCK: I should have surmised this. For the creature to be able to use gravity as a propulsive force, it would have to have this capacity.

48. The Immunity Syndrome (Robert Sabaroff)
KIRK: Spock, you may have been right. We've lost contact with the Intrepid and we're out of communication with an entire solar system. Any update from Starfleet?
UHURA: I cannot filter out the distortion, sir. It's getting worse.
KYLE: Captain, deflector shields just snapped on.
KIRK: Slow to warp three.
KYLE: Warp three, sir.
SPOCK: Indications of energy turbulence ahead. Unable to analyse. I've never encountered readings like this before.
…
SPOCK: It is not liquid, gaseous, or solid, despite the fact we cannot see through it.
KIRK: So far that's not much help.
SPOCK: It is not a galactic nebula such as the Coal Sack, and since our deflectors were activated by it, it would seem to be some form of energy, but nothing our sensors can identify.
…
CHEKOV: Penetration of the zone in one minute, seven seconds, sir.
KIRK: Red Alert. Deflectors full power. Phaser banks ready.
CHEKOV: Phasers standing by. Deflectors at full power, sir.
…
KIRK: Kirk to Engineering. Scotty, there was a power loss. How come?
SCOTT: We lost five percent of our energy reserve, sir. Our deflector shields are weakened.
…
KIRK: We'll find out what it is, but we'd better get out of here ourselves. Scotty, channel all the impulse and warp power into one massive thrust forward. That might snap us out of the zone.
SCOTT: Aye, Captain, but I'll reserve some for the shields in case we don't get out.
SPOCK: I submit, Mister Scott, if we do not get out, the shields would be extraneous. It would only prolong our wait for death by a short period of time.
KIRK: Use whatever power is necessary to get us out of here, Scotty. Report to your stations, continue your research. Dismissed.
…
KIRK: The closer we get, the faster our energy drains out. We're barely surviving at this distance.
MCCOY: Perhaps we could risk the shuttlecraft. Perhaps with a protective shield
KIRK: I'm not sending anyone anywhere. Unmanned probes can give us the information we need to destroy this thing, if it can be destroyed.
…
SPOCK [OC]: Diverting all secondary power to the shields. (McCoy enters) I'll continue communications as long as there is power to transmit.
SCOTT: Captain, he won't have enough power to get back out if he diverts it to his shields.
KIRK: Spock.
SPOCK [OC]: I heard, Captain.
…
(Spock is thrown around in the shuttlecraft, everyone on the ship just feels a jolt.)
KIRK: Report, Mister Spock. Spock, report.
SPOCK [OC]: I am undamaged, Captain. Relay to Mister Scott I had three percent power reserve before the shields stabilised.
…
CHEKOV: Sir, Mister Spock has reduced life-support systems to bare minimum.
KIRK: Spock, save your power for the shields.
SPOCK: Calculations indicate the shields will last only forty seven minutes.
…
SCOTT: Captain, the pull from that organism is increasing, and the power drain from our shields is getting critical.
KIRK: How much time do we have?
SCOTT: No more than an hour now, sir.
KIRK: Put all secondary systems on standby. Shield power has unconditional priority.
SCOTT: Aye, sir.
UHURA: Captain, I'm receiving a message from Mister Spock on a low-energy channel. It's faint, but it is readable.
KIRK: Put it on, Lieutenant.
UHURA: On audio, sir.
SPOCK [OC]: This is Spock.
SPOCK: I am slowly losing life support and minimal shield energies. According to my calculations…
…
SCOTT: We're down to forty three percent, sir. We're slipping a bit against the pull that beastie's putting on us.
SCOTT [OC]: We can't last more than forty five minutes at this rate of decline. Less, if I have to apply more thrust.
KIRK: What would happen if you diverted all remaining power to the shields, except for impulse power, keep that in reserve?
SCOTT: Cut the engine thrust? We'd be sucked into that thing like being caught in a wind tunnel, sir.
KIRK: Exactly. Prepare to divert power on my signal. Kirk out.
…
KIRK: Ready, Scotty.
SCOTT: Switching power to shields. Impulse in reserve. Cutting thrust to zero, now!
KYLE: Impact five seconds.
(There's a big bump and people are thrown all over the place. Then there is calm.)
CHEKOV: We're through, sir.

50. By Any Other Name (D.C. Fontana & Jerome Bixby)
ROJAN: Captain, you think you are unconquerable and your ship impregnable, but while we've talked, the capture has already begun.
CHEKOV: Something penetrating from the planet.
SCOTT: Increase power to shields.

53. The Ultimate Computer (D.C. Fontana)
SPOCK: Phaser hit on port deflector four, Captain.
…
SPOCK: Minor hit on deflector screen four. No appreciable damage.
…
SPOCK: M-5 has identified her, Captain. The Woden. Listed in Starfleet Registry as an old-style ore freighter converted to automation. No crew. Coming into visual range.
SULU: Captain, deflector shields just came on.
CHEKOV: Speed increasing to warp three, Captain.
KIRK: Lieutenant, get Daystrom up here. Disengaging M-5 unit. Cut speed to warp one. Navigator, go to course one one three mark seven. I want that ship given a wide berth.
…
(Four starships just like Enterprise are in formation as Kirk, Spock and McCoy arrive on the bridge.)
UHURA: Enterprise to USS Lexington. Come in, Lexington. Sir, I can't raise them. M-5 is blocking all frequencies, including automatic distress. Just a minute, sir. Captain, I'm getting audio signal from the Lexington.
KIRK: Put it on.
WESLEY [OC]: Enterprise from USS Lexington. This is an M-5 drill. Repeat. This is an M-5 drill. Acknowledge.
UHURA: Captain, M-5 is acknowledging.
KIRK: Daystrom, does M-5 understand that this is only a drill?
DAYSTROM: Of course. It was programmed to understand, Captain. The ore ship was a miscalculation, an accident. I don't know
CHEKOV: Sir, deflector shield just came on. Speed increasing to warp four.
SULU: Phasers locking on lead ship, sir. Power levels at full strength.
KIRK: Full strength?
MCCOY: If that thing cuts loose against unshielded ships, we're in
KIRK: That's no miscalculation.
SPOCK: Attack force closing rapidly, breaking formation, attacking at will.
SULU: Our phasers are firing, sir.
SPOCK: Hit on the Lexington.
…
M5: This unit must die.
(It disconnects itself from the power feed in Engineering and goes dark.)
KIRK: M-5?
CHEKOV: Sir, deflector shields have dropped.
SULU: All phaser power gone, sir.
…
SPOCK: The force field is gone, Captain. M-5 is neutralised.
SCOTT: System's coming back. I can give you power for the shields, sir.
KIRK: I need communications.
SCOTT: That'll take longer.
KIRK [OC]: Then cut power.
SCOTT: Sir!
KIRK: Cut power. Keep those shields down.
…
WESLEY [OC]: Break off attack. Do not fire. The Enterprise has dropped her shields. I repeat, hold attack. Do not fire.

55. Assignment: Earth (Art Wallace & Gene Roddenberry)
Captain's log. Using the lightspeed breakaway factor, the Enterprise has moved back through time to the twentieth century. We are now in extended orbit around Earth, using our ship's deflector shields to remain unobserved. Our mission, historical research. We are monitoring Earth communications to find out how our planet survived desperate problems in the year 1968.
(The ship rocks as if being hit by something.)
KIRK: Alert status. Force shields on maximum. Leslie, begin sensor scan.
SPOCK [OC]: Transporter room to Captain.

[blackbat242]

I noted this in your listing:

44. Journey to Babel (D.C. Fontana)
...
CHEKOV: Number four shield has buckled, sir.
KIRK: Auxiliary power.
CHEKOV: Switching over. Shields firming up. Number four is still weak, sir. If they hit us there again, it'll go altogether.
...
CHEKOV: Number two shield is gone.

[Starbeard]

Good catch! I could've sworn at first I saw two instances of shield facings being mentioned, but when I pasted them all together I could only find the one example. Thanks for pointing that other one out.

It occurs to me that both episodes were written by Dorothy Fontana, and shield 4 is mentioned in both, once as the port screen. I'll bet she envisioned 4 screens, starting from 'fore screen 1' and moving clockwise around the ship, so the port screen is #4.

[blackbat242]

Nice for 2-dimensional protection, but there would be #5 & #6 for top/bottom as well, space being 3-D.

[starcruiser]

I always liked the 6 sided shield idea, though it should be fore - aft - port - starboard - dorsal - ventral...

Also, I felt like there probably should be both shield and screens, with the screens being used as an initial buffer (and for navigation) and the shields up close and more like a proper barrier. It seems like that may have been the idea by the time of ST:TMP.

[blackbat242]

Yes - deflectors being the low-level passive defense, on "automatic" (computer-controlled) functioning, to deal with meteors (micro & macro), and general naturally-occurring energy fields & fluctuations (cosmic rays, etc) - and shields being high-level active defenses controlled by the bridge crew (and engineering, etc) to deal with high-level energy fields/beams (normally associated with direct attack by hostile beings).

[Starbeard]

These are good points. I've always fallen back on calling them both deflectors: the 'deflector screen/shields' are the high-powered defensive shields, and the 'navigational deflectors' are the always-on, low-powered version that deflects stellar debris out of the way as the Enterprise zips through space. This is the definition used in all the early writer's guide, and subsequently in the early gaming & reference material.

However, I'm no longer entirely convinced of it. Like you've mentioned, starcruiser, I think by TMP there was a conceptual division between passive deflectors and the active shields. Also, I've gone through Season 3 now and can't find any reference to the term 'navigational deflectors'; the closest any scripts come to it is in The Paradise Syndrom (Season 3), where the Enterprise has to use its 'deflectors' to knock a meteor off-course from its eventual path of destruction against a planet. Either way, in the scripts the terms 'deflectors', 'shields' and 'screens' seem to have been tossed around interchangeably to describe a few different things. Whatever the writing guide says about the terms can't be taken as being any more correct than anything else that's been used.

As a side note, I'm not sure when the big sensor dish at the front of the ship was determined to be the navigational deflector (or deflector + sensor array)—maybe an early TNG episode, or some ship blueprints if it was before that.

[Starbeard]

The 6-sided, 3D shielding definitely works best, especially when translating into a hex-based starship combat game. Since those are typically 2-dimensional, the 6 shield facings not only map out well with the 6 hex sides, but also helps explain the 3D abstraction, by pretending that in reality those 6 facings are somehow covering the ship like a cube.

I'll put the Season 3 references up when I get a chance to edit them, but from them I found that:
1. Shield facings were almost exclusively used by Dorothy Fontana. Elaana of Troyius, the only 3rd season script to utilize them, was written by John Meredyth Lucas—and actually in much more depth than any of Fontana's scripts (he wrote an extended scene where the Enterprise is attempting to manoeuvre its weakened shield facings away from the enemy, etc.)
2. Fontana mentions 'port deflector 4', and 'shield 2'. Lucas mentions 'forward shields' and a flank '#4 shield'. 1) Fore - 2) Starboard - 3) Aft - 4) Port seems the presumed arrangement, whether or not dorsal/ventral facings are included (which they probably should be).

It occurred to me that keeping only 4 shield faces could be used to sort of retroactively explain why Star Trek space fights are always basically 2-dimensional. If each of the four facings creates a sort of hemisphere shape, then in order to successfully cover the whole ship in a full shield bubble they would have to overlap at the seams, so to speak. This would make the top and bottom of the ship much stronger, being overlapped four times over with shielding. Starship captains know that the best way to get a good hit on a target is to engage it on a flat plane, where the shields are less dense.

[starcruiser]

The dish on the Enterprise was always called the "Main Sensor" by Matt Jefferies. It was changed to a Navigational Deflector in TNG and I always had issue with that. A simple deflector screen stretched out in a parabolic cone in the direction of flight would probably be fine for most sublight navigation, and I doubt anything would be needed beyond light speed.

I would think that the "deflector beam" used in Paradise Syndrome may have been a specialized mode or temporary setup to deal with the asteroid threat and may have involved reversing the effect of the tractor beam for that purpose. There is so much in TOS that wasn't solidly nailed down either on screen or in the writer's guide...

[Starbeard]

I think it is best to consider the deflector beam effect in the Paradise Syndrome as a temporary setup for the purposes of the story. Perhaps it was performed by reconfiguring the tractor beam, or else it used that and the navigational deflectors in combination—but either way, it doesn't seem like it should taken as representative of normal operation.

[Starbeard]

Here are the season 3 references to deflectors/screens/shields. In this season the writers explored more of how the the shields are powered and how that affects other systems, and what types of assault they are and aren't effective against. Hopefully all of these citations can be combined into at least a semi-consistent account of how shields might work for an original series game, and how well the different rule sets out there reflect that.

Season 3 Deflector References

56. Spectre of the Gun (Gene L. Coon)
KIRK: Our orders are very clear. We're to establish contact with the Melkotians at all costs.
SPOCK: True telepaths can be most formidable, and we have been warned.
KIRK: What previous contacts have been made with the Melkotians?
SPOCK: No recorded contacts. If they ever ventured into space, they evidently withdrew immediately.
KIRK: Lieutenant, hailing frequencies.
UHURA: Tied in, sir.
KIRK: This is Captain James T. Kirk of the starship Enterprise, representing the United Federation of Planets. We've contacted your buoy and understand its message. We hope that you will understand that our intent is to establish peaceful relations with you. Lieutenant, answer?
UHURA: Nothing, sir. Clear on all frequencies.
KIRK: Try again.
UHURA: Still no response, sir.
KIRK: Opinion, Mister Spock?
SPOCK: I prefer being a welcomed guest, Captain, but there seems to be little choice.
KIRK: None whatsoever. Mister Chekov, deflectors at full intensity. Increase speed to achieve planet fall as scheduled.
CHEKOV: Aye, sir. Standard orbit in five minutes.
…
SPOCK: Captain, the Melkotian object.
KIRK: Sensor readings.
SPOCK: The object is beginning to emit M-rays of a highly unstable nature, Captain.
KIRK: Lieutenant, sound Red Alert. Mister Chekov, deflector shields on full. Phaser gun crews, lock on target.

57. Elaan of Troyius (John Meredyth Lucas)
SCOTT: I've got bad news, Captain. The entire dilithium crystal converter assembly is fused. No chance of repair. It's completely unusable.
KIRK: No chance of restoring warp drive?
SCOTT [OC]: Not without dilithium crystals. We can't even generate enough power to fire our weapons.
…
KIRK: They're trying to force a fight. Scotty, what's our energy status?
SCOTT: Ninety three percent of impulse power, sir.
SPOCK: We can still manoeuvre.
SCOTT [OC]: Manoeuvre? Aye. We can wallow like a garbage scow against a warp-driven starship. Our shields will hold for a few passes, but without the matter-antimatter reactor, we've no chance. Captain, can you not call Starfleet on this emergency?
…
KIRK: This is Captain James Kirk of the USS Enterprise on Federation business. Our mission is peaceful, but we're not prepared to accept any interference.
KLINGON [on viewscreen]: Enterprise, prepare to be boarded or destroyed.
KIRK: I'd say our strategy wasn't totally effective.
SULU: Captain, the Klingon ship is closing on an intercept course. Five hundred thousand kilometres. Deflector shields up.
KIRK: Scotty, can you give me partial power on the phaser banks?
SCOTT [OC]: No, sir, not a chance.
…
(Weapons fire hits the Enterprise)
SPOCK: He's passed us. All shields held.
KIRK: Mister Sulu, bring her to one four three mark two. Keep our forward shields to him.
SULU: Here he comes again, sir.
KIRK: Stay with the controls. Keep our forward shields to him.
SPOCK: Better than warp seven.
KIRK: Hard over, Sulu. Bring her around. He's going for our flank. (another disruptor hit) Sulu!
SULU: Sorry, Captain. She won't respond fast enough on impulse.
SPOCK: He's past us again. Damage to number four shield.
KIRK: How bad?
SPOCK: It will not withstand another full charge, Captain.
…
KIRK: Mister Sulu, prepare on my order to turn quickly to port. Try and protect the number four shield.
SULU: Aye, sir.
KIRK: Now, Sulu. hard a-port!
(Another disrupter hit)
SULU: Shields holding, but weakened, sir.
UHURA: Captain. Message coming in.
KLINGON [on viewscreen]: Enterprise, our readings confirm your power extremely low, your shields buckling. This is your last chance to surrender.
SULU: Captain, number four shield just collapsed. Impulse power down to thirty one percent.
…
KIRK: You and Spock get up here. Sulu, prepare for warp manoeuvres.
SULU: Aye, sir.
KIRK: Chekov, arm photon torpedoes.
CHEKOV: Photon torpedoes ready.
SULU: Warp power to the shields, Captain?
KIRK: Negative. His sensors will pick up our power increase. The more helpless he thinks we are, the closer he'll come. As he passes, I want to cut in warp drive. We'll pivot at warp two and bring all tubes to bear.
SULU: Aye, sir.
…
KIRK: Warp in, Scotty. Full power to shields.
(The Klingons fire.)
KIRK: Warp factor two. Bring us to course one four eight mark three.
(The Klingons fire again)
KIRK: Chekov, photon torpedoes. Fire!
CHEKOV: Aye, sir.
(Six torpedoes go, but not all hit the Klingons)
SULU: Direct hit amidships by photon torpedo.
SPOCK: Damage to Klingon number three shield. Number four shield obliterated. Loss of manoeuvre power.
CHEKOV: He's badly damaged, Captain. Continuing away at reduced speed.

58. The Paradise Syndrome (Margaret Armen)
KIRK: It's like discovering Atlantis or Shangri-la. Mister Spock, is it possible there's a more evolved civilisation somewhere else on this planet, one capable of building that obelisk or developing a deflector system?
SPOCK: Highly improbable, Captain. Sensor probes indicate only one type of life form here.

59. The Enterprise Incident (D.C. Fontana)
SCOTT: But, sir, what about Mister Spock?
KIRK: We'll just have to hope he can buy us enough time to get this cloaking device installed.
SCOTT: It'll have to hook into our deflector shield control.
KIRK: Can you do it?
SCOTT: I don't know, sir.
KIRK: You have fifteen minutes, Scotty.

64. The Tholian Web (Judy Burns & Chet Richards)
SULU: Mister Spock, we're being fired upon.
(The ship shakes to the impact of the blasts of energy.)
SPOCK: The renowned Tholian punctuality.
UHURA: Mister Spock, damage control report. Minor structural damage to sections A4 and C13.
SPOCK: Engineering, hold power steady and cut off all unnecessary expenditures. Mister Sulu, divert all but emergency maintenance power to the shields.
SULU: But sir, that'll reduce our phaser power by fifty percent.
UHURA: Mister Spock!
(Another bolt of energy is heading towards them.)

66. Day of the Dove (Jerome Bixby)
KIRK: An entire human colony, a whole settlement. One hundred men, women and children. Who did it? And why? (communicator beep) Kirk here.
SPOCK; Spock here, Captain. Sensors have picked up a Klingon ship, closing fast.
KIRK [OC]: Deflectors on. Condition Red. Protect yourselves.
KIRK: Total reply if attacked. So that's the answer. Klingons.

68. Wink of an Eye (Arthur Heinemann & Gene L. Coon)
KIRK: The fact remains, when we beamed down there we couldn't find these people. They were there, now they're not. Nor is Crewman Compton.
SPOCK: It would seem that some force or agent only partially discernible to our instruments may have been responsible.
KIRK: Mister Sulu, I want the ship on standby alert while we continue the investigation.
SULU: Sir, now I have readings that deflectors are inoperative. The controls are frozen.
KIRK: Scotty, assist. Mister Spock, ever since we beamed up from Scalos, we've had a series of malfunctions. I want an investigation and an explanation

70. Let That Be Your Last Battlefield (Oliver Crawford & Gene L. Coon)
SPOCK: Nothing identifiable. The craft appears to be built for speed rather than combat.
KIRK: Something out there can't be seen. Explanation?
SPOCK: None. Completely elusive. In fact, it's invisible.
KIRK: Invisible. Malfunction?
SPOCK: There is no sensor failure. The readings persist.
CHEKOV: It's headed straight for us!
KIRK: Evasive action.
CHEKOV: It shifts with us, sir. And we're pushing to the limit!
KIRK: Deflector shields activated, Mister Sulu.
SULU: Automatic, sir.
CHEKOV: We're on collision course.
SULU: It's out of control or a suicide mission.
KIRK: Sound warning for collision. Red Alert.
SULU: Brace yourself for collision. Brace yourself

73. The Lights of Zetar (Jeremy Tarcher & Shari Lewis)
SULU: Captain, it's approaching at warp factor two point six and accelerating.
KIRK: Check that. No natural phenomena can move faster than the speed of light.
SPOCK: It is definitely doing so, Captain. Therefore it cannot be a phenomenon of nature.
KIRK: Deflectors on. Condition yellow.
UHURA: Condition yellow, sir.
SULU: Shields activated, Captain.
…
SULU: Captain, it's heading straight for us.
KIRK: Activate shields.
SULU: Shields activated.
KIRK: Mister Chekov, change course to one four three mark three.
CHEKOV: One four three mark three.
KIRK: Storm's course, Mister Sulu?
SULU: One four three mark three.
KIRK: …It's clear we can't outrun them. Can we shield against them?
SPOCK: I do not believe the Enterprise shields would prove an effective defence.
…
SULU [OC]: Sulu, Captain. All evasion tactics carried out as ordered.
KIRK: What success did you have?
SULU [OC]: It’s been useless, Captain.
SPOCK: At their present force, they will get through the shields this time, Captain.
KIRK: Warp eight, Mister Sulu.
SULU [OC]: Yes, sir.

[Starbeard]

Here's a separate transcript for the Paradise Syndrome, since it features the Enterprise's attempt to deflect the asteroid, as well as an obelisk that described as "one huge deflector mechanism". Neither of these seemed like they were talking about quite the same thing as standard deflector shields, so I set them aside.

58. The Paradise Syndrome (Margaret Armen)
SPOCK: If we are to divert the asteroid which is on a collision course with this planet, we must warp out of orbit within thirty minutes. Every second we delay arriving at the deflection point compounds the problem, perhaps past solution.
…
SPOCK: Doctor, that asteroid is almost as large as your Earth's moon. Far enough away, the angle necessary to divert it enough to avoid destruction is minute, but as the asteroid approaches this planet, the angle becomes so great that even the power of a starship
MCCOY: The devil with an asteroid! It won't get here for two months, Spock!
SPOCK: If we arrive at the deflection point in time, it may not get here at all.
…
SPOCK: (picking up two stoned to illustrate his point) Doctor, assume this is the planet we're on. This is the approaching asteroid. If we don't get to that deflection point in time, it will become physically impossible to divert this asteroid. In that case, everyone on this planet will die, including the captain.
…
(The Enterprise has arrived at the asteroid.)
…
CHEKOV: Deflection point minus four.
SPOCK: All engines stop. Hold position here.
SCOTT [OC]: All engines stop, sir.
SPOCK: Prepare to activate deflectors.
SULU: Aye, sir.
CHEKOV: Power dropping, sir.
(The lights dim.)
SPOCK: Engineering, maintain full power. Full power.
SCOTT [OC]: Dilithium crystal circuit's failing, sir. We'll have to replace it.
SPOCK: Not now.
CHEKOV: Zero. Deflection point now, sir.
SPOCK: Activate deflectors.
(A beam shoots out and pulses against the big lump of rock.)
CHEKOV: Power dropping, sir.
SPOCK: Degree of deflection, Mister Sulu.
SULU: Not enough, Mister Spock. It's only point zero zero one three degrees.
SPOCK: Recircuit power to engines. Maximum speed heading three seven mark zero one zero.
SULU: Aye, sir.
CHEKOV: That heading will put us directly in the asteroid's path, sir.
SPOCK: Correct, Mister Chekov. I intend to retreat in front of that asteroid until we can employ all power on phaser beams.
MCCOY: What for?
SPOCK: To destroy it. A narrow beam concentrated on a single spot will split that mass.
MCCOY: It might also cripple the ship, and we would be crushed by the asteroid.
SPOCK: Incorrect. We'll still be able to get out of its path by use of impulse power.
MCCOY: Jim won't be able to get out of its path.
SPOCK: That, Doctor, is another calculated risk we must take.
…
SPOCK: Captain, were you inside this structure?
KIRK: Yes. What's inside is loaded with scientific equipment.
SPOCK: This obelisk is one huge deflector mechanism. It is imperative that we get inside immediately. Captain, we do not have much time.
SPOCK: If we are not able to gain entry and activate the deflector mechanism within the next fifty minutes, this entire planet will be destroyed.
…
KIRK: Scotty, if the deflector isn't activated within twenty minutes, get out of orbit. Get the Enterprise out of the danger zone. The landing party is expendable. The Enterprise isn't. Kirk out. Miramanee. Bones, stay with her. Do what you can.
SPOCK: It is similar to deflector panels I've seen, Captain, but far more complicated.