''Super Mario Bros. X'' is a downloadable PC Mario fangame that borrows elements from ''VideoGame/SuperMarioBros'', ''VideoGame/SuperMarioBros2'', ''VideoGame/SuperMarioBros3'', ''VideoGame/SuperMarioWorld'', and ''VideoGame/NewSuperMarioBrosWii'' among numerous other games. The game was created by Andrew "Redigit" Spinks of ''VideoGame/{{Terraria}}'' fame, before he got a purported cease-and-desist letter from Creator/{{Nintendo}} and left the engine in the hands of the community. The game is most notable for its ''huge'' LevelEditor, which allows the player to make their own levels using the numerous blocks, items, and [=NPCs=] available from the aforementioned games.

Due to the legal circumstances explained above, we can't really provide a link to the download, but a quick Google search should do the trick.

Note: please only include tropes related to the engine itself, and the official episodes released from the old SMBX site. Games made in this engine, should they have enough unique tropes of their own, should get their own page.

''VideoGame/MakeAGoodLevelX'' has its tropes on its page.
!!"The Invasion 2" contains examples of:
* ActionGirl: Princess Peach is playable here, and can use all the same power-ups that Mario can.
* ArtShift: The stage Retroville has entirely 8-bit styled graphics. [[DevelopersForesight This stays true even if you bring in a power-up that isn't otherwise available in the level]].
* AscendedExtra: Three rare, yet [[EnsembleDarkhorse popular]] {{Power Up}}s from ''Super Mario Bros. 3''--[[TakenForGranite Tanooki Suit]], [[DropTheHammer Hammer Suit]] and [[GiantFootOfStomping Kuribo's Shoe]]--get a lot more screen time in this fangame.
* AsTheGoodBookSays: Surprisingly, the default end credits sequence present in the engine contain a passage from [[Literature/TheBible Colossians]].
%%* BonusBoss: [[spoiler:Mother Brain exists in one of the Metroid-styled "Pwnhammer" levels.]]
%%* BrainInAJar: [[spoiler:Mother Brain.]]
* ColorCodedForYourConvenience: The Yoshis and shoes.
* DifficultySpike: The dungeons are much harder and longer than the levels.
* DiscOneFinalBoss: [[spoiler:Bowser is merely the boss of World 4, and is fought as in ''Super Mario Bros.'' However, he appears again as the FinalBoss, and this time you fight him like you did in Super Mario Bros. 3.]]
* DistressedDamsel: Peach is playable, so Daisy takes this role. [[spoiler:You rescue her in World 4, about halfway through the game.]]
* DummiedOut:
** There are a few [=NPCs=] that aren't used in the episode at all, but are still in the editor, such as the regular Propeller Block.
** There are two [=NPCs=] in the [[spoiler:"Lakitus are throwing Lakitus" menu]] that aren't available elsewhere: a blue shell-less Koopa that doesn't work with throw blocks and doesn't have an animation for emerging from a shell (the shell-kicking Koopa was added before regular SMW Koopas) and a ridable airship piece that works like a slower and less useful Clown Car.
** Checking the sprite sheet will reveal Peach and Toad had some extra animations, like the former having a unique full-speed running animation and the latter being able to slide down slopes and ride Yoshi. They cannot do either in the final game.
* ExcusePlot: Daisy explains that Bowser is recruiting other villains. Said other villains appear very sporadically, and not always on the main path.
%%* FiveManBand:
%%** TheHero: Mario.
%%** TheLancer[=/=]TheSmartGuy: Luigi.
%%** TagalongKid: Toad.
%%** TheChick: Peach.
%%** TheBigGuy[=/=]GuestStarPartyMember: [[Franchise/TheLegendOfZelda Link]].
* TheGoomba: From four games!
* [[GuestFighter Guest Player]]: Link from ''Franchise/TheLegendOfZelda'' series. His sprites and moveset are cribbed from VideoGame/ZeldaIITheAdventureOfLink.
** Version 2.0 also includes [[Franchise/MetalGear Solid Snake]], [[{{VideoGame/Knytt Stories}} Juni]], [[Franchise/TheLegendOfZelda Zelda]], [[{{Franchise/Metroid}} Samus]], Franchise/MegaMan, and {{VideoGame/Klonoa}}. However, due to their unusual game mechanics they typically have to have levels made specifically for them.
* GuideDangIt: Many of the secret exits. A lot of them require you to have a specific powerup and keep it for the whole level so you can reach the exit with it.
* InfinityMinusOneSword: The Hammer Suit. Unlike in ''VideoGame/SuperMarioBros3'', you can now throw hammers in two different arcs--high and low. Throwing them at a low trajectory is the default attack, making it easier to aim it than in its origin game. And ''like'' in ''Super Mario Bros. 3'', it retains the same [[GameBreaker gamebreaking]] lethality, being able to take out virtually every enemy in the game with relative ease.
* InfinityPlusOneSword: [[spoiler:The Lakitu's Shoe, which provides unlimited flight]]. You need all seven Stars to access it, so that requires completing everything at least up to Dire Dire Rocks, one of the last levels in the game.
* KaizoTrap: "A Short Level" lives up to its name, but it's not ''quite'' as short as it first appears. [[spoiler:If you take the [=SMB3=]-style exit like you've been using for the whole game, you merrily walk into a pit and die. You have to continue past the exit sign, leap over said pit, go down a pipe, and continue on to a SMW-style exit (read: goal post) to actually complete the level. By the way, the springboard in front of said goal post is a red herring--the goal post actually is the end, and perfectly safe to go through.]]
%%* NintendoHard: Oh yes, is it ever!
* NoFairCheating: Using any of the cheat codes will disable the ability to save. [[spoiler:Untill you type in "redigitiscool" on the map screen, at which point you can save again.]]
* NonIndicativeName: The "Pwnhammer" levels, which are ''VideoGame/{{Metroid}}'' themed. One Toad even {{lampshade|Hanging}}s it.
** Also the dungeons, which at first somewhat appropriately evoke DoomyDoomsOfDoom (the Dungeon of Pain and the Dungeon of Agony) while later being given increasingly over-the-top and silly names (the Dungeon of Strange Happenings and the Dungeon of Inappropriate Phrases), while simultaneously getting [[NintendoHard much harder]].
* NostalgiaLevel: There are a ''lot'' of them. Most of them are part reproduction and part new content. Of note:
** Super Easy Road and Flying Raccoon Zone both have clear references to the first stage of ''VideoGame/SuperMarioBros3''.
** Subcon Nightmare Land is a lot like the first stage of ''VideoGame/SuperMarioBros2''.
** Go Go Goomba has references to ''Super Mario Bros.'' 1-1.
** The Dungeon of Inappropriate Phrases has a mazelike structure similar to that of some castles in ''Super Mario Bros.''
** One level seems self-aware of this, called Super Nostalgia World. It contains ''VideoGame/SuperMarioWorld'' content.
** The Retroville level shamelessly dishes out the nostalgia with its [[{{Retraux}} 8-bit-styled sprites]].
* PowerUpMount:
** Yoshi, per usual. He even comes in [[ColorCodedForYourConvenience seven different colors]], each with its own unique abilities.
** The Kuribo's Shoe and its derivatives.
** The Clown Car, which is used in only one level.
* PunnyName: [[VideoGame/{{Portal}} The Water is Not a Lie]]. A [[SubvertedTrope subversion]] in that in the ''original'' invasion, water physics did not yet exist, so the level was called "The Water is a Lie"; the current name is actually based on this.
* {{Retraux}}: You'll see a lot of this. Especially in the Retroville level, mentioned above.
* SchmuckBait: One of the cheats is "donttypethis". [[spoiler:It causes bombs to rain from the sky]].
* TheSpiny: From two games! Interestingly, only the SMW version comes in an egg form, because [=SMB3=] Lakitu throws green chasing Spiny eggs (the SMW Lakitu can be set to throw '''anything''', [[spoiler:including itself, if you look hard enough]]).
* SuperStar: {{Averted|Trope}}. Redigit was well known for being vehemently against adding this during the game's development, since he thought it would be misused, as in ''VideoGame/SuperMarioFlash'''s levels. Instead, the Stars act as collectibles, as in ''VideoGame/SuperMario64''.
** The aversion is averted with Super Mario Bros X 2.0, where there is a Super Star in development.
* VideogameSettings:
** GreenHillZone: [[VideoGame/SuperMarioBros3 Mushroom Plains]] and [[VideoGame/SuperMarioBros1 Koopa Kingdom]], as well as [[VideoGame/SuperMarioWorld Dino Island]] to an extent.
** UndergroundLevel: [[VideoGame/SuperMarioBros2 Subcon Underground]].
** DeathMountain: Dino Island.
** ShiftingSandLand: Hurtful Hotlands.
** TheLostWoods: The Rawest Forest. One of the levels there is even ''called'' the Lost Woods (although it's an intentional reference to ''VideoGame/TheLegendOfZelda'').
** PalmtreePanic[=/=]UnderTheSea: Wet Water Zone.
** LethalLavaLand: The Lava Hole.
* WarpWhistle: The Star Palace acts as this, in addition to providing free power-ups, since through it you can access any world in which you've found the Star Warp.