First, let's start with the High Grade (HG) grade. This grade is one of the most common and widely available, making it a popular choice for beginners. HG kits are typically smaller in size and have fewer pieces, making them easier to assemble. They also have a lower price point compared to other grades, which makes them more affordable. However, this does not mean that they are of lower quality. In fact, the HG line has greatly improved over the years, and some newer HG kits have almost as much articulation and detailing as the more expensive grades. HG kits are great for beginners or those who want to build a quick and easy kit.
On the other hand, the Real Grade (RG) grade offers more details and articulation than the HG grade. They are similar in size, but the RG line offers a more realistic build with a higher number of parts. The RG line also offers more detail, with intricate parts and decals that make the model look more like the actual mobile suit from the series. The articulation in the RG line is also more advanced, allowing for a wider range of poses. However, this level of detail comes with a higher price point and a more complicated build process. RG kits are great for intermediate to advanced builders who want a more challenging build and a more realistic representation of the mobile suit.
Another difference between the HG and RG lines is the inner frame. The RG line typically includes a more detailed inner frame, adding to the realism of the model. In contrast, the HG line often has a simpler inner frame that is easier to assemble. This is not always the case, as some newer HG kits have also started to include more detailed inner frames.
In conclusion, the main difference between HG and RG kits is the level of detail, articulation, and price point. While HG kits are great for beginners and those who want an easy build, RG kits offer a more realistic and challenging build with a higher level of detail. Ultimately, the choice between the two grades depends on the builder's skill level, preferences, and budget.