The term Gunpla refers to mecha models, characters, or plastic vehicles from the Japanese franchise Gundam offered by Bandai. It symbolizes the abbreviation "Gundam plastic model". They first appeared in 1980.

THE GUNPLA PHILOSOPHY: THE MODEL FOR EVERYONE! No glue or paint required.

All Gundam models are characterized by two key elements:

• the parts are nestable
• and they are colored in the mold.

Gunpla are categorized in order (known as "grade") according to their quality and/or size. The main categories are:

• NG No Grade (1980), retrospectively referring to the first models introduced in 1980.
• HG High Grade (1990), the first line of higher quality in 1/144 scale.
• MG Master Grade (1995), higher quality than HG High Grade with fully modeled internal mechanisms in 1/100 scale.
• PG Perfect Grade (1998), the most technically advanced line in 1/60 scale.
• FG First Grade (1999), the budget-friendly clip-on series.
• HGUC High Grade Universal Century (1999), a popular re-release of the Universal Century robots.
• EX-model (2001), a line dedicated not to robots but to vehicles and related flying machines.
• MS Mega Size (2009), 1/48 scale series.
• RG Real Grade (2010), similar to MG Master Grade with an advanced internal framework but in 1/144 size like "HG High Grade".
• RE/100 Reborn One Hundred (2014), a new series of gunpla in 1/100 scale.
• Super Deformed Gundam or SD Gundam is a Japanese animation franchise, whose works are parodies of the Gundam saga, adopting the graphic codes of super deformation.

However, the exhaustive classification is much more complex as it depends on the scale (ranging from 1/550 to 1/35), the upgrades (the master grade line comes in versions 1.5, 2.0, and 3.0), and special events (for example, a Ver.G 30th series was released for the franchise's thirtieth anniversary).