Hey good question. The core rules for harm are 'fiction first'; assign the injury that makes sense within the fiction according to the level of risk, and if it makes sense that one of your injuries would affect a die roll, it is hindered. There's no limit to how many injuries you can have of any severity, and you'll only die from sustaining multiple injuries if it make sense in the fiction. That said, if you're risking outright death and roll 1-2, then you die immediately regardless of how healthy or uninjured you are. The risk of death again depends on the fictional positioning.
1400 Below, on the other hand, has a fixed number of injuries you can have. They hinder in the same way as the core rules and you can still die outright when risking death, but if you sustain a second injury after already taking a minor wound, then it's 'upgraded' to moderate, and the fiction adjusts accordingly. This means that the most number of injuries a character can receive without healing is three (or four if you take the Brute spec.). Overall, this makes characters more likely to die, but gives the players a more concrete idea of their risks/closeness to death.
The intent is that 1400 Below is grittier and darker than the rest of the games (characters are numerically weaker) and characters are more likely to die through just normal play (as opposed to big, life-risking acts).
Got it, thank you! After reading a bunch of the 2400 games I am starting to get a feel for the writing style and format. I was subconsciously filling a lot of gaps with my own RPG baggage.
By the way, I love the spell dice system in MAGE, I will like,y include something like it in any fantasy/weird fiction 1400 or 2400 game I play. Can’t wait to run it