Was going to skip this one the first time around, but changed my mind.
V4 is a fork of Angband by the devteam of Angband themselves. Over the years they've copped a lot of flack from the player community for various changes they've introduced to Angband - many seem to believe that Angband is and ought to be an essentially complete game, which should be receiving maintenance and bugfixing, rather than development. Or disagreements about the pace or style of changes introduced.
The idea behind V4 is that in this branch the devs can trial more radical changes which, once they are polished and perhaps come to be well-regarded, might get ported to the main game, 'vanilla' Angband (also known as V (this terminology greatly pre-dates V4 itself)).
One change from Angband that I was playing previously (but which is in the latest official releases also), is the inclusion of a high quality tileset provided by Shockbolt as the default presentation, rather than ASCII. Wanting to surprise people with that is one reason I intended to skip V4 for the time being, before coming to what passes for my senses.
There is a handy text file available from the new game menu which explains the main changes in V4 from Vanilla Angband, most of which boil down to object generation: As best I can tell, objects have been streamlined so that there are now the basic object types and then variations magical or otherwise are applied to these as modifiers. E.g. there are no longer the objects 'fur cloak, mithril plate, blade of chaos'. Instead there are cloaks, plate armours and swords which might be generated with the corresponding affixes and thus possess the appropriately modified properties. This applies all the way from the very mundane items to the very powerful, but not to artifacts, which are the same as ever. More or less.
Item identification has been adjusted so that player characters, once they learn about properties on a particular item, will recognise those same properties on other items without having to go through the identification rigamarole again. Referred to as 'rune based' ID.
Combat revisions have been made in an attempt to force decisions to be more interesting - players now have 'finesse' and 'prowess' skills, and weapons have 'balance' and 'heft' qualities, which work best with particular combinations of these skills. Monsters now have an 'evasion' rating which affects how well they evade attacks, and instead of its former role in evasion, monster armour now affects how much damage a monster will absorb from hits.
Nope, can't describe those any better. Haven't played it yet. Let's find out!
Looks like our first victim will be a female hobbit mage, named Ezelin. All details randomly selected.
In the town, Ezelin buys a cloak from the general store before heading down into Angband. It may be foolhardy, but it seems easier to learn item changes by exploring instead of shopping. Apart from her new cloak, Ezelin carries only a book of basic magic spells, three rations of food, a scroll of Word of Recall, three wooden torches, and a dagger.
Level 1: This seems a quiet, peaceful place.
Here we learn that as an incentive to exploration, level feelings have been split. Rather than appearing all at once when you enter a new level, we first get a sense of how dangerous the level is, and only after exploring for a bit do you get the part of the feeling for how valuable the treasure is.
The first life Ezelin encounters in Angband is a white icky thing. It sleeps in the corner of a room and, seeing no need to disturb it, Ezelin leaves it be. The second is a grey mushroom patch. Unsure in the dim torchlight exactly how close her path comes by, Ezelin accidentally steps beside it.
The grey mushrooms release spores reflexively, confusing Ezelin. She attempts to retrace her steps, but in her confusion walks into a wall instead. The grey mushroom patch continues releasing its spores. Ezelin almost immediately dies from the toxic effect they have on her body.
Hobbit mages. They're vastly more fragile than Half-Troll Priests. Although there has been a concerted effort to make the game harder since version 3.2.0, I don't think that had anything to do with Ezelin's untimely end. Possibly that the radius of torchlight has been reduced, leading to her fatal misstep.