Frame Break

And sometimes, you get *literal* examples.

A Painting the Medium and Medium Awareness trope, where characters interact with the confines of the scene. For example, interacting with borders around comic strip panels by crashing through the side or falling out the bottom. In live action media, it might be that it is implied that two characters are in a different settings, in different buildings, yet one of them can reach into the other setting.

A Sub-Trope of Odd-Shaped Panel and Ninja Prop.

Examples of Frame Break include:

Advertising

Occasionally seen in television commercials, where a "consumer" might reach across a Split Screen to take the product.

Anime and Manga

Dragon Ball: Once, Goku is hit so hard he bounces off the edge of the panel.
Obligatory Mahou Sensei Negima example: Negi, Blue with Shock, holds on to the frame in a "Kilroy was here" pose when he contemplates what Evangeline's going to do to him for losing the ring she gave him.
When a character is formally introduced in One Piece, they often stand outside the panel, overlapping it.

Comic Books

She Hulk did it occasionally in her Genre Savvy / Medium Awareness days. One issue of She Hulk has her ripping through two pages of (fake) ads to go after a villain.
Ambush Bug once jumped back several pages to rescue Cheeks.
"Little Sammy Sneeze" by Winsor McCay used this as early as the 1900's.
Kitty Pryde, in some comics, can phase through panels.
A recent issue of Superboy had Doomsday actually a clone of him smash through the entire bottom half of a page in attacking Superboy, destroying the frames in the process.
Has been used in The Beano a number of times and in the Beano Video as well.

Live-Action TV

One Monty Python's Flying Circus animation had a Comic Book superhero bouncing off the walls of his panel in an attempt to escape.
In Police Squad!, when Frank Drebin visited the crime lab and Ted Olsen led him to the next room, Olsen would go through a door -- and Drebin would step around the end of the stub wall in which it was built.
The "Lost Session" teaser trailer for Netflix's Cowboy Bebop makes extensive use of Frame Breaks, with characters constantly grabbing, moving and even wielding the borders between frames.

Music Videos

The video for Vienna Teng's "Level Up" effectively does this in live action with each set splitting apart to reveal the next as she travels through them.

Newspaper Comics

Pearls Before Swine does this several times, as well as "Panel Walking" between comics.
- Pearls once had a joke that relied on proper placement in the paper. One day, Family Circus had Billy denying that he was spilling sunflower seeds in the kitchen. The Pearls strip that day had Rat throwing sunflower seeds down and out of the panel. When positioned directly above Family Circus, Rat's abuse of the long-running comic became apparent.
Every so often a character in Pogo would literally lean on the fourth wall this way (or at least against the frame border); on occasion Albert would use it to strike a match for his trademark cigars.
Little Nemo in Slumberland used this on occasion. In one strip, Flip tears off the bottom frame of a panel and uses it to knock down letters from the comic's logo.

Video Games

Comix Zone makes use of this trope, as it takes place in a comic book. Not a comic book world, the actual pages.
Jump Super Stars - You can punch through the "panels" and then do extra damage by hitting enemies out of the "comic".

Web Comics

Casey and Andy comic #6.
Only the outsiders of Project 0 break panel to show that they aren't bound by reality.
Order of the Stick plays with this sometimes. Haley gets knocked into the next strip in the fight with Tsukiko. (The strip in question is called "At Least It Wasn't the Fourth Wall This Time.")
- Haley also climbs up the 'panes' of the cast page to borrow a diamond from herself.
In the Art Shift chapter of Welcome to Convenience Store.
In this Square Root of Minus Garfield, Garfield breaks through all the panels to get a cookie jar that's just two seconds out-of-sync.
Cyanide & Happiness has a few examples:
- In this strip a blow-up doll explodes and breaks the frame.
- And another shown above where a fat guy breaks the limits.
- Interestingly enough another fat guy has one here
- And more recently here
This The Book of Biff panel and all the others that same week.
Apelad's Laugh-Out-Loud Cats.
- Pushing or pulling on the frame: #523, #865, #1210, #1256, #1359, #1645.
- Outside the frame: #350, #504, #1197.
- Frame destruction: #402, #495, #616, #1416, #1508-1510 #1651, #1654.
From Keychain of Creation: Nemen Yi is a master of Infinite Canvas Style. High-level Exalted are just that good.
- Including using part of the frame as throwing knife.
Gunnerkrigg Court got a more subtle variant in this little incident.
- Here, a massive fire spreads beyond the panel borders, and even onto the following page (an effect that will presumably be more impressive in the print version).
Rock, Paper, Cynic used panel-breaking as a version of two-dimensional time travel in the comic, "Time Travel".
- We see a similar trick in "Free," where a stickman tries to dig his way out of the frame.
The Way of the Metagamer does this. A lot. Looking at previous and future panels, climbing between panels, and even pulling a section out of a panel are common occurrences.
Footloose may provide the most triumphant example. Faerie pirates cast a spell that lets them fire a cannon through the side of the panel and into the next.
The aliens in the webcomic One Small Step grab the corners of the panel so they can pull apart from being stuck.
Schlock Mercenary likes to show characters leaning into frame and holding onto the panel borders (for example, here). Also, done with a chainsaw.
In xkcd, frame breaks you!
- A Fourth Wall Psych: "Further Boomerang Difficulties"
Tallyho: paws on the frame to address us.
In Unbound, events sometimes spill over the sides of the comic. In one case a fire spreads to the 'paper' of the website's background, leaving it blackened once the fire is out.
In Unsounded, weird supernatural stuff—like certain fires, or metaphorical snake skeletons—extend off the page. When the characters walk through a dark tomb, the entire webpage is darkened.
Bob and George. During the Mega Man 5 parody, the protagonists split up and the comic began running two strips per day so the plots for both groups could update concurrently. After about a month of these updates, the characters in the bottom strip began wondering how their allies were doing, so they climbed into the strip above them to ask.
In Mixed Myth, Tamit learns the secret of Time Travel, and it involves seeing the comic panels. She then demonstrates her mastery by reaching through time (i.e. across the panel borders) to poke someone in an adjacent panel.
In this Out at Home strip, Penny bats a speech balloon from one frame to another.
Gavin, the main villain of The Fancy Adventures of Jack Cannon, here tries to trap the titular hero in a shrinking panel frame, and Jack has to break it to escape.

Western Animation

In The Fairly OddParents, when Timmy magically goes into the Crimson Chin comic book, he's able to jump from frame to frame (and time travel by doing so).
In the intro of The Beano Video we see numerous instances of this including Teacher being used by the Bash Street Kids as a battering ram.