Gundam Sentinel is a photonovel series, one of many Gundam side-stories taking place in the Universal Century timeline. Written by veteran Masaya Takahashi, it takes place during the final phase of Mobile Suit Zeta Gundam and the early stages of Mobile Suit Gundam ZZ in Universal Century 0088. The story shows the efforts of The Federation to stop an insurrection by elite Federation officers, former Titans calling themselves the "New Desides". "Task Force Alpha", formed by a conglomerate of Federation soldiers, Anti-Earth Union Group and Karaba veterans, equipped with some of the most advanced mobile suits of the era, is sent to quell the uprising.
What's noteworthy about Sentinel is the debut of prolific mechanical designer Hajime Katoki, the artist behind other iconic Gundams in the franchise such as the V2 Assault Buster Gundam, Wing Gundam Zero Custom and the Gundam Unicorn. Sentinel is regarded as one of the most well known Gundam side-stories to have been published, and is usually noted by fans for having one of the most mature plots in the franchise.
Tropes associated with the Gundam Sentinel are:
- Ace Custom: Three Z-Plus A1 units were decked out in white and orange demonstration colors (versus the standard gray with blue trim), one of which is said to belong to Amuro himself.
- Alice Allusion: "ALICE" is the artificial intelligence installed in the MSA-0011 S Gundam, and "she" gradually gains self-awareness over the story.
- Ascend to a Higher Plane of Existence: The narration over ALICE's Heroic Sacrifice implies she may have done so rather than cease to exist.
- Benevolent A.I.: ALICE, as despite being a combat AI who is trapped in a borderline And I Must Scream situation for her entire existence, she becomes genuinely heroic and sacrifices herself to save her pilots.
- BFG, Wave-Motion Gun: FA-010A FAZZ's "Hyper Mega Beam Launcher", MSZ-006A1 Z Plus and S Gundam's "Beam Smartguns". The AMA-100 Z'od-iacok, a mobile armor over 200 meters in length, splits down the middle to reveal an absurdly huge beam cannon.
- BFS: The story takes place during the brief surge of popularity for the giant beam sabers pioneered by the ZZ Gundam, which could also be used as heavy-duty beam cannons when 'sheathed'. Several suits have them mounted, including the FAZZ team, the S/EX-S Gundam, and the Gundam Mk. V (the last of which gets particularly good use out of them thanks to its extreme mobility).
- Big Bad: Brave Cod, the leader of the New Desides, is the main antagonist leading their rebellion. After he's killed, Tosh Cray takes his place.
- Call-Forward: The Gundam Mk. V was created as the predecessor to the Doven Wolf from Mobile Suit Gundam ZZ. Though out of universe it was designed much later, in-universe it's a Super Prototype whose design was simplified and mass-produced by Neo Zeon after Sentinel's ending.
- Civil War: The New Decides are Titans remnants and sympathizers, who're later joined by the Tenth Divisional Fleet that was supposed to assist Task Force Alpha.
- Combining Mecha: The S Gundam has a core fighter system and two other flying components, much like the ZZ Gundam.
- Cyber Cyclops: The Xeku Eins deployed by the New Decides have a Zeon inspired mono-eye.
- Decoy Protagonist: Ryo Roots is The Hero, but ALICE gets much more Character Development and is the one who actually saves the day.
- Elite Mooks: Sentinel gives us the "Zeta Plus" family, limited mass-production versions of the venerable Zeta Gundam.
- Evil Former Friend: Tosh Cray used to be a close friend to Task Force Alpha's commander Stole Mannings. It's telling that he tried to stop the Zod-Iacock from firing at Stole's Nero Trainer, to no avail.
- The Federation: Actually proactive for once!
- Face–Heel Turn: The Tenth Divisional Fleet; said fleet commander, Admiral Brian Aeno, chooses to help the New Desides after a New Desides representative approaches and convinces him to turn Heel, instead.
- Fun with Acronyms: MSA-0011(Ext) Extraordinary Superior (Ex-S) Gundam, but that can't compare to "Advance Logistic & Inconsequence Cognizing Equipment" (ALICE).
- Greater-Scope Villain: Neo-Zeon, who secretly supports the New Desides against Task Force Alpha and even gives them the mobile armor called Zod-Iacock.
- Heroic Sacrifice: ALICE ejects the 3-person core fighter to save her pilots, then shoots down the New Desides shuttle and the remaining Z'oon with a single shot. Then S Gundam explodes in Earth's atmosphere.
- Humongous Mecha: It's part of the Gundam series, so yeah.
- Interquel: Although Gundam ZZ has already started by the time Gundam Sentinel begins.
- Lightning Bruiser: The ORX-013 Gundam Mk-V is so fast it nearly kills New Desides Ace Pilot Brave Cod the first time he uses it. That aside, the mobile suit allows Brave to become a One-Man Army, single-handily wiping out over a dozen Task Force Alpha mobile suits, including their three FAZZ units, before Ryu and ALICE in the Ex-S Gundam finally bring him down.
- Mecha Expansion Pack: This story is the one that really introduces the concept into the franchise. The S Gundam has a booster variant, the Ex-S Gundam is basically a stronger S, and the "Deep Striker Gundam" is the S with so many boosters, fuel tanks, guns, shield generators, and sensor packs added on, it barely looks humanoid and recognizable. The FAZZ is this to the MSZ-010 ZZ Gundam, alongside a Zeta Plus variant with heavy boosters attached.
- In fact, the FAZZ has so much extra armor and weaponry that it can no longer transform/combine. Accounts differ on whether the core ZZ Gundam is still able to split up after jettisoning its armor or if it's custom-built as one piece for added stability.
- On the opposite side, the RMS-141 Xeku Eins has at least 3 different mission configurations.
- Portmanteau: Overlaps with Punny Name; in Universal Century, space colonies are grouped into clusters called "Sides" - hence, New Desides come from the words "decision" and "dissident".
- The Ex-S ("excess") Gundam, which set a new gold standard in ridiculously overbuilt mechanical designs.
- Shout-Out: All members of New Desides are based on The Shinsengumi.
- Super Prototype: Played with - the FAZZ and Zeta Plus are essentially production versions of the ZZ Gundam and Zeta Gundam, respectively.
- The FAZZ was made as a testbed for the ZZ's "Full Armor" parts, before Judau Ashta got them in that series. In a subversion, the parts do work as planned, but because the unit itself was gutted for cost purposes (leaving out the Full Armor parts' "Anti-Beam Coating", for example), it's considered an inferior unit to the ZZ. The fact all three are destroyed by Brave Cod says something about this.
- The Zeta Plus, on the other hand, saw considerable service (mostly out of the spotlight) as a good, useful unit. The main S Gundam pilots even use them as training units, since they weren't given access to it at the time.
- And then there's the S (Superior) Gundam and it's Mid-Season Upgrade, the Ex-S (Extraordinary Superior) Gundam, which both Katoki and Takahashi seemed to consider a Lightning Bruiser
Game-Breaker. Game depictions range from "very useful" to "better than the Nu Gundam".
- Theme Naming: Most of the characters are named after historical figures from the Bakamatsu period of Japanese history. The naming tends to follow a specific pattern - the first name is translated directly into English while the surname is an English homophone of a portion of the original Japanese name (for example, Isami Kondo -> Brave Cod; Ryoma Sakamoto -> Ryo Roots ("moto" means "base" or "root" in Japanese)).
- The Smurfette Principle: Played with; the only active female character is ALICE, and even then she's merely an AI without a humanoid appearance.
- Transforming Mecha: With the series's proximity to Zeta and ZZ this was a given.
- The Ex-S transforms into a massive spacecraft. As the model kits reveal, this is done by linking the two fighters formed by the S Gundam with all the excess boosters, similar to the G-Fortress mode of the Gundam ZZ.
- The "Zeta Plus" Mobile Suits, based on the Zeta Gundam, transform to waverider modes as well.
- Averted with the FAZZ which, though based on the transforming ZZ Gundam, had the combining transforming gimmick jettisoned for better performance as a standard MS.
