Recent PowerPoint features behave differently in earlier versions

Charts

If the presentation contains a chart where the cells appear outside of the supported row and column limit, those cells will not be saved and will not appear.

Drop shadows

Soft, outer shadows are converted to hard shadows that you can edit.

Gradient outlines on shapes or text

Unavailable.

Heading and body fonts

Heading and body fonts are converted to static formatting. That is, when you open the file in an earlier version of PowerPoint you cannot change the text or the style formatting.

Levels of indentation

Some indentation levels are unavailable.

Multiple columns of text

These cannot be edited

Sections

Slides will not be grouped into sections

Shapes with or without text

These cannot be edited

SmartArt graphics with or without text

The SmartArt graphic or the text in it cannot be edited

Static Guides

If you add static guides to the slide master or to a layout in Slide Master view, the guides won't appear when opened in earlier versions of PowerPoint.

Strikethrough and double-strikethrough on text

Unavailable.

Text effects, such as shadows, reflections, and glows

Unavailable.

Themes

Some themes with shapes and placeholders can change them into pictures, which you cannot edit.

Transitions

A transition effect first released in version 2013 won't be available earlier versions of PowerPoint.

Video

Media clips inserted will be saved as pictures

WordArt Quick Styles

Unavailable.