Talk:Blink

Ultima IV (DOS) - Technical Details

I didn't want to get too technical in the article so sticking code details here instead.

First you need to understand that as you walk around Britannia there is a 32x32 area that is loaded into one struct and used for a lot of things. When you get within 5 tiles of the edge of that 32x32 area the entire thing shifts by 16 tiles.

That area is used by the blink spell. It scans to the edge of that 32x32 area and then walks back towards the character looking for the first valid tile and blinks you there. Which, due to the way the 32x32 square is moved around, means you can usually blink back the way to came further than you can blink the way you are going. And that some tiles blink to different locations depending on which direction you approach them from.

The list of valid tiles includes things like boats but you can't blink to them. I believe because the blink spell is looking at the map itself and not at items on the map.

There is also an exclusion zone around the the Isle of the Avatar anywhere that your current x and y coordinates are larger than 0xc0 (192) it will straight up fail the spell without checking valid tiles at all.

I tried to use the way the the 32x32 block moves around to get into the Abyss even with the exclusion in place but couldn't get it to work. If the Abyss was moved, like, 5 squares further up with the exclusion zone moved with it then it would be possible to blink in. It IS possible to get to Hythloth via blink if you go sail south from it and get just outside the exclusion zone (e.g. A'A", O'I") and blink north. -- Fenyx4 03:09, 13 September 2020 (UTC)