Single (or two) posts, which has round lamp in top of it.
Star Posts (再スタート・マーカー,Sai Sutāto Mākā?, lit. "Sai Start Marker") also referred to as Point Markers (ポイントマーカー,Pointo Mākā?), Lampposts, and Check Points, are distinguished markers and common objects in games of Sonic the Hedgehog series. Star Posts made their first appearance in Sonic the Hedgehog (1991) and serve as the series' progress markers and are found exclusively in the Zones. Passing through a Star Post, makes the players' progress up that point in the Zone will be saved and when the player loses a life on the same place, the playable character will start over at the point of the last Star Post they passed.
Star Posts are similar in design to, but smaller than, street lights in real life, as the design of Star Posts has been simple and tends to be the same throughout the series: a yellow/blue post and a stretch rod with a bulb on the top. The way the rod spins has varied, but usually in 2D games it rotates 360 degrees twice and after that goes to the same vertical position while the bulb part changes its color or flickers. Star Posts have a different appearance in 3D titles from Sonic Adventure onwards, as there are two posts on opposite ends of each other, creating a gate the player can pass through. While going through the Star Posts, both lamp parts start spinning above the posts twice until they get to the vertical position. Games such as Sonic Unleashed and console versions of Sonic Generations, the passage in-between two posts is widened particularly in 3D areas to make it easier to pass through. Certain games in the series don't use Star Posts as check points at all and have completely different objects being used (see here).
The first appearance of Star Posts is in 16-bit version of Sonic the Hedgehog, where they originally were called Lampposts in the American instruction manual of the game. Lampposts have a simple design with a yellow post, grey stretch rod and a blue bulb on the top. When Sonic touched a lamp post, the bulb changed colors from blue to red. These lamp posts were used as checkpoints, which started as a tradition in the series.
If the player touches a Star Post and has over 50 rings, a lamp starts flashing red and yellow while spinning Star Circle appears above it. If the player jumps into the ring, he/she is transported to a Special Stage, where the player has to collect amount of rings to get one of Chaos Emeralds. If the player doesn't enter to the star circle it will disappear after while. After Special Stage the player will be transported back (with zero rings) to the Star Post where the star circle was located.
In the locked-on game Knuckles in Sonic 2, Knuckles retains the number of Rings he had at the last touched Star Post when respawning the stage at that point or after entering a Special Stage, which makes earning the seven Chaos Emeralds from all Special Stages easier.
Sonic the Hedgehog CD
Star Posts appear in Sonic the Hedgehog CD, once again called Lamppost in the instruction manual. They also have a similar design as the original Sonic the Hedgehog, with a yellow stylistic post, grey stretch rod and a blue bulb on the top.
Sonic the Hedgehog 3 & Knuckles
Star Posts make an appearance in Sonic the Hedgehog 3, its add-on continuation Sonic & Knuckles and the lock-on Sonic the Hedgehog 3 & Knuckles. Star Posts have a similar design to Sonic the Hedgehog 2, with a slight difference. The Star Circle also appears, though entering it now takes the player to a Bonus Stage rather than a Special Stage. If the player collects over 50 rings and enters the star circle in Sonic the Hedgehog 3, the player will be sent to a Gumball Machine type of Bonus Stage where he or she could collect power-ups such as lives, elemental shields, and rings. Different looking Star Posts are also featured in the Competition Mode of Sonic the Hedgehog 3 as a starting point and goal.
With Sonic the Hedgehog 3 and Sonic & Knuckles combined, the player is able to transport into all three Bonus Stages after passing Star Posts with certain amount of Rings. As collecting 20-34 Rings, the player transports from yellow star circle into Rotating Maze/Slot Machine type Bonus Stage, getting 35-49 Rings will transport from red star circle into Glowing Spheres type Bonus Stage and getting 50 and more Rings transports from silver star circle into regular Gumball Machine-type Bonus Stage.
Sonic the Hedgehog Triple Trouble
The Game Gear counterpart of Star Posts, Arrow Monitors, appear in Sonic the Hedgehog Triple Trouble. Like in the 8-bit version of Sonic the Hedgehog, breaking it saves progress. Arrow monitors don't appear in act 3 of zones, although one was featured in the third act of last zone, Atomic Destroyer Zone.
Star Posts are replaced by Giant Rings as check points in Sonic 3D Blast, which are actually used to lead Flickies of the island into it. If the player lose a life, they restart at the point where the Giant Ring was located.
The Game Gear counterpart of Star Posts, Arrow Monitors, appear in Sonic Blast, as destroying an arrow monitor will save the game's progress. Arrow Monitors don't appear in third acts of zones, which feature bosses.
Star Posts, now renamed Point Markers, make an appearance in Sonic Adventure. Point Markers have red colored posts and blue round centers with yellow star symbols on them, while on top of them is a blue bulb that turns yellow when it reaches the vertical position.
The game introduces the concept of a two posts gate in action stages, where the player can go through them to save their progress and also give a time bonus between the earlier posts to the current ones.
Point Markers make another appearance in Sonic Adventure 2, having the same design from Sonic Adventure. Point Markers can also earn the player items depending how many rings he or she has when they pass through the Point Markers. Having more than 20 rings gives 5 rings more; over 40 rings gives 10 rings more and more than 60 gives 20 rings more. With over 80 rings it starts giving Speed Up immediately and with over 90 rings the player is given a Shield.
Sonic Advance games
Point Markers make appearance in all Sonic Advance games, being called Check Points and resembling those from Sonic Adventure. In Sonic Advance there are now only 2 check points in each act of a zone. In Egg Rocket Zone, there are no check points, but the game save its progress four times at certain sections as the rocket starts out of launch section and removes portions of rocket during the flight until its reaching to end of earth's atmosphere.
Checkpoints in Sonic Advance 2 are different looking, as having a post with orange and white stripes and its lamp part is blue while it have rotating "C" on it, which blows to yellow orb as the player goes through it. In the game, there are now more checkpoints than two in each act. Checkpoints also don't appear in boss act of the stages.
In Sonic Advance 3, Checkpoints return their design from Sonic Advance, but these objects are now also located more than 2 checkpoints per one act. Checkpoints don't appear in vs. boss act of the stage.
Check Points make an appearance in Sonic Heroes with a complete redesign, as they are now are plates which have red circles on the ground with a yellow star inside them, surrounded by a blue glow. Passing through them saves the player's progress and gives a Power Core to whichever character is in the lead.
Shadow the Hedgehog
Checkpoints, renamed Save Points, appear in Shadow the Hedgehog. There is not a yellow star nor is there a blue glow, but it will save the player's progress and allows the player to warp to other points they have visited before. This can be very useful if the player forgets something at another point of the stage.
Sonic Rush series
Checkpoints also appear in both Sonic Rush games and have a similar function to Checkpoints in 2D games: saving the player's progress and allowing the player to start from the last Checkpoint if they lose a life. In Sonic Rush, Checkpoints are similar to those from Sonic Heroes, while in Sonic Rush Adventure, Checkpoints have a spinning ring above the chalice and a yellow star at the center. As the player goes through, the ring disappears, and the star turns yellow and starts spinning slowly. This also fills up the Tension Gauge.
Sonic the Hedgehog (2006)
Point Markers reappear in Sonic the Hedgehog (2006), with the returning same design as the Sonic Adventure games. It likewise saves the player's progress and gives a time bonus.
Sonic Rivals games
Although Star Posts don't appear in Sonic Rivals and Sonic Rivals 2, there are similar kinds of posts that are at the start point and act as a goal sign. Both of posts have a round star sign on top of them.
Point Markers appear in Sonic Unleashed, once again called Check Points and saving the player's progress. Check Points look like a gate with lamps hidden; the lamps open up when the player crosses it. The interval between the posts has been expanded considerably so a player can not miss the Check Point. Also posts have a light laser between on them. In the PlayStation 3/Xbox 360 version, the checkpoints also record Sonic's speed at the moment he passes through it. As PlayStation 2/Wii versions have mission based levels, Check Points don't appear at all.
Sonic the Hedgehog 4
Star Posts appear in both episodes of Sonic the Hedgehog 4, having the same design from Sonic the Hedgehog 2 and being more detailed in Episode II. In both episodes it serves as a checkpoint from which the player can restart if he or she loses a life.
Checkpoints make another appearance inSonic Colors. Instead of the lamps hidden like in Sonic Unleashed, they are in position similarly to Sonic Adventure. The Wii version has the Point Makers design while the Nintendo DS version features its design from Sonic Rush. There are no Checkpoints at all in Terminal Velocity.
Star Post make an appearance in Sonic Generations, where they are nearly the same as in Sonic Colors with the exception of having light in the middle instead of light lasers. Star Posts appear in both classic and modern acts and several challenges. When passing through it a time is shown on the screen showing the time difference the player took to pass through it between their fastest run and the current run
Sonic Lost World
Star Posts make another appearance in Sonic Lost World, repeating its role and having the same look from Sonic Generations. However, Star Posts haven't been seen to feature light lasers or lighting in the middle, and when the player transports to the two dimensional sections of the zone, there is only one Star Post seen instead of a two posts gate. Nevertheless, the Nintendo 3DS version of the game seem to use two Star Posts gate even in 2D sections. In the Wii U version, when the player loses more than once, the floating Item Box with wing mark shows up above Star Posts, that after breaking it, transports the player to the next Star Post, thus skipping the section in the Zone. In the 3DS version, a Special (golden) RC Vehicle appears when the player has loses lives enough times.
Sonic Boom: Shattered Crystal
Star Posts make another appearance in Sonic Boom: Shattered Crystal, where they repeat its role from main games. However, they have slightly different high-tech look and the only known major difference in this incarnation of them is that after passing through them, a tick sign will appear.
Star Posts make another appearance in Sonic Runners, where they function both as regular check points and deposit banks to carry all previously collected rings. This time, there are only single Star Posts in each section either after beating Dr. Eggman and speeding up the running pace or at the middle-point of the stage usually at the higher pathways.
Arrow Monitors (マーカー,Mākā?, lit. "Marker") are the replacement of Star Posts in Game Gear and Master System games, as these objects appear in the 8-bit version of Sonic the Hedgehog, Sonic Triple Trouble and Sonic Blast. It is usually a monitor with a red or yellow "↓" icon on it. By breaking the monitor, it will save the player's progress. Arrow monitors don't appear in the 8-bit version of Sonic the Hedgehog 2, although unused in-game graphics are in the game's data.
Bells (ベル,Beru?) are replacements of Star Posts that only appear in Tails Skypatrol. The yellow bell floats in the air, and when the player touches it as Tails, it will save the player's progress. The player also starts from the last bell after losing a life.
Check Points (チェックポイント,Chekkupointo?), also referred to as Checkpoints or Save Points, are variants of Star Posts that appear in Sonic Heroes, Shadow the Hedgehog, Sonic Rush, Sonic Rush Adventure and Nintendo DS version of Sonic Colors. Check Points are usually plates with red circles on the ground and a yellow star inside them, surrounded by a blue glow. In Sonic Heroes Check Points awards the player with a Power Core depending who's in the lead, while in Shadow the Hedgehog, it can warp the player to other Check Points the player has visited before.
Apperances in other media
Sonic the Comic
In Sonic the Comic, Star Posts appeared frequently in early issues. Star Posts existed all over planet Mobius. They can be activated by Sonic the Hedgehog when he runs around the post at super speed, which creates an energy field on the bulb through which anyone can jump. In this way, the Star Posts allowed instantaneous travel to any other Star Post, as well as access to the Special Zone (which in the comics was an alternate dimension).
As the most common method of access to the Special Zone, Doctor Robotnik attempted to use the Badnik Sonic to destroy the Special Zone when he set up his Special Zone Egg Fortress, but he was thwarted by Sonic.
In Archie's Sonic the Hedgehog comics and its spin-offs, Star Posts are a device built by Rotor which allows Sonic and Tails to enter the former Zone of Silence. After the gathering, it has been transformed into a world which resembles both the Special Stages from Sonic 2 and Sonic 3 & Knuckles. It is here that the now seven Chaos Emeralds reside.