Autoplay

Autoplay, also known as auto-forward or just auto, is a common accessibility feature found in some games that can make text advance automatically without the player having to manually advance it after each line of dialogue appears.

The feature can usually be turned on and off at any time by the player, usually through a quick menu button. And it usually has settings that affect how fast it advances.

It can be useful for people who find it hard to frequently press buttons or who want to play the games while doing something else at the same time. But if it changes the text too fast, the player could need to pause it and re-read stuff.

Time calculation

Typical factors that might be used to determine how long to show the text incude:

• A per-character delay, so longer text is shown for longer than shorter text. This delay might be set directly by the player or developer, or it might be calculated from a "characters per second" variable that's set by the player or developer.
• A fixed delay, independent of the length of the text, to make sure really short texts still get shown long enough to be read comfortably.
• Additional fixed delays in response to sprite changes, expression changes, CGs, or other visual changes that might give the player a reason to look a bit more closely before the text changes again.
• A per-word delay might be available in some engines.
• Additional delays on punctuation marks.
• Additional variable delays might be applied when the text contains uncommon words or characters. Especially the first time they appear in the game.
• If there's voice acting, the duration of the voice lines might be used directly or as a factor in deciding when to advance the text.

Since people would rather wait a fraction of a second too much than a fraction of a second too little, it's probably a good idea to keep the default speed a bit slow. A possible initial value could be 8 characters per second plus a 1.5 second length-independent delay. But it can depend on the text, font size and other factors.