"So many heroes from so many dimensions! This is pretty cool!"
A
crossover that involves characters from more than two shows or more than two
fictons.
More often than not, this is a mash up of series which do not have a strict sense of continuity or a clear
Universe Bible. To lessen
canon-faulting, especially with series that do have strict continuity, a new 'neutral' setting is made that offers equal footing for all the characters.
This rarely occurs in live action shows, unless a production company can be formed that holds copyrights to everything. Thus, this is much more common in animated series — although you can generally expect
The BBC to pull one out of somewhere when
Children In Need or
Comic Relief rolls around.
It also becomes more viable the farther you get from
canon, such as one-time TV specials and especially video games (
Kingdom Hearts,
Jump Super Stars,
Super Robot Wars, etc.)
As
Story Arcs have become more prevalent, this practice has somewhat lessened, with shifts to strict
Verse building and explicit references.
This trope has become increasingly common in video games, especially those involving both licensed and original properties. These games, depending on how far or how deep they mine, can have interesting effects on the fiction chosen. Many long-gone and/or forgotten
Humongous Mecha shows, for example, often get a new lease on life, or even a brand-new sequel or remake, after making an appearance or two in a
Super Robot Wars game. Similarly, the
Fire Emblem series was finally brought over to the US to great success after two of its characters made an appearance as unlockable fighters in
Super Smash Bros Melee.
In spite of its recently emerging prevalence, this trope is
Older Than Feudalism. The
Argonautica by Apollonius Rhodius (3rd century BCE) features nearly every ancient Greek mythical hero all going on a quest to find the Golden Fleece.
Sub Tropes:
See also
Power Creep, Power Seep and
Story-Breaker Team-Up.
All Stories Are Real Somewhere is related.
Examples