I spent a lot of time familiarizing myself with crawl code a while ago, but didn’t feel like I understood the game itself well enough to make a good contribution. Since then I’ve played a lot, and have been thinking about artifacts recently, so here are some ideas I came up with. Let me know if there are any that would be worth my time to implement and make a pull request for.
scarf of visibility
contam
stealth -inf
+1 los
full los halo
evoke to mark self
thoughts: mark is risky but potentially extremely powerful in a good location. Other properties are a relatively minor mixed bag. Currently there are no scarf unrands in game so I feel like something should be done
lead ball
orb
+6 str
offhand punches do 2x damage
thoughts: basically a 2h weapon for unarmed; decent but probably worse than shield or 2h for other melee. Potentially good for VS/Ds that want a fast 1h and str for their innate auxs
100 pound ring
drain
non artifact weapons that do not have the heavy brand are treated as if they also have the heavy brand
thoughts: the restriction to non artifacts feels awkward, but it would probably break things without it. Needs drain to prevent swapping too often
+0 wind up arbalest
modified arbalest base type
base delay is 1.0 and not reduced by ranged weapons skill, but is affected normally by other factors
base damage is multiplied by delay
thoughts: good early game weapon for a lot of characters, good 0 skill ranged option for melee dex chars, potentially powerful build with heavy armor+tower shield. Might be too strong and tedious with melee dex because you want to swap when things get into melee, but being 2h may mitigate this. Hard to say how good it would be with heavy armor and tower shield, enchantment and base type may need tweaking
-1 slippers of reckless speed
speed
+blink
*tele
*shaft (duplicates explore shaft chance without the restriction to once per branch)
thoughts: sounds funny but probably not a good idea. If it were implemented it might need contam to prevent it being used only when you want *tele and *shaft.
+10 staff of fury
staff (5 dam, +5 acc, .6 min delay at skill 12)
contam
wiz
archmagi
int+10
str+10
casting spells has a 33% chance to berserk you (or heavily contaminates you if you’re immune)
thoughts: gives melee chars on demand berserk and occasional access to useful spells, at the cost of a bad base type and no swapping. A questionable option for casters wanting to transition to melee. Numbers probably need tweaking
Xom’s Dice
infinite charge misc evocable (to replace chesspiece)
every use guarantees 1d3 extremely good random effects
2-10% (based on evo) chance for 1d3 extremely bad random effects per use
(e.g. with 0 evo the second use has a 10% chance of bad effects, the third 20%, fourth 30%, etc.)
thoughts: seems more interesting than xom’s chesspiece to me. based on risky dice from hxh