Signposts

Signposts, which are also known as Goal Plates and Bonus Plates(ボーナスプレート Bōnasu purēto?), are one of the most stable objects of the game franchise. The signposts are usually found at the end of the first, second, and sometimes third act of a zone. By default, each one displays a picture of Dr.Robotnik(Eggman) before the player passes it. Afterwards, the signpost will spin several times before revealing the image of the character who passed it. Besides signalling the end of a Act/Stage, signposts also gives points, Gold Rings, 1-Ups, and Continues. In Sonic 3 & Knuckles, signposts sometimes release monitor/item boxes if the player jumps repeatedly towards it. Its variants is the Goal Ring and Time Warp Plates.

Time Warp Plates
Time Warp Plates(タイムワーププレート Taimuwāpupurēto?), also known as Past and Future Signposts, are special signposts exclusive to Sonic CD. These allow Sonic to travel to different time periods, which is one of the main features of the game. Depending upon which Time Warp Plate Sonic passes, it changes the setting of the Act/Stage accordingly along with affecting how the Present will be afterwards. However, it is only accessible after he has gained and maintained enough momentum to warp to that time period.

Also See

 * Goal Ring
 * Capsule
 * Metal Sonic Projectors
 * Eggman's Machines