Kill Tracker: Weapon Growth

Every weapon remembers who it's killed. Land the finishing blow on another player, and if that weapon has never killed them before, it permanently gains +1 Attack Damage — for good. Kill the same person again with that same sword and nothing extra happens; the bonus only comes from new victims.

No commands to run, no config to edit. Install it, fight, and watch your favorite weapon get sharper the more legendary its body count becomes.

Features

• Per-item tracking — the bonus lives in the weapon's own data, not your player profile. Hand your battle-worn sword to a friend (or lose it to a looter) and the power goes with it.
• Unique kills only — repeatedly killing the same player with the same weapon won't stack the bonus. Every point of damage represents a genuinely new victim.
• Works on any weapon — sword, axe, trident, even a stick if that's really what you want to fight with.
• Zero setup — drop it in your datapacks folder and it's live. No commands, no items to craft, no scoreboard to initialize by hand.
• Visible in the tooltip — the attack damage bonus shows up automatically when you hover the item, like any other enchantment or attribute.
• Lightweight — runs entirely off an advancement trigger on player kills. No tick-based loops, no background processing eating server performance.

How it works

1. You kill another player while holding a weapon.
2. The datapack checks that weapon's kill history for that specific player's UUID.
3. If they're not on the list yet: the weapon's stored kill count goes up, a new attack damage modifier is written to match, and you get a message and a level-up jingle.
4. If they are already on the list: nothing changes — no double-dipping.

Over time your weapon becomes a real trophy: a sword that's beaten five different rivals in melee is measurably deadlier than a fresh one off the crafting table.

Installation

1. Download the .zip file — don't extract it, Minecraft reads datapacks directly from the zip.
2. Drop it into your world's datapacks folder: saves/<YourWorld>/datapacks/
3. Run /reload in-game, or restart the world.
4. You'll see a [KillTracker] datapack loaded. message in chat once it's active.

Compatibility

• Minecraft version: 1.20.1
• Works in survival, PvP servers, and SMPs. Best suited for worlds where player-vs-player combat is a regular part of the game — arenas, factions, kits-PvP, or just a rowdy SMP.
• Should coexist with most other datapacks. It only adds one custom attribute modifier (tagged internally so it won't collide with other packs' enchantments) and doesn't touch vanilla loot tables, recipes, or advancements players actually see.

Notes

• The "who did I just kill" check looks for a nearby player at 0 health within a short radius, so it's built around ordinary melee PvP kills. Extremely simultaneous multi-kills in the same spot are the one edge case that isn't perfectly disambiguated.
• The bonus applies to whatever's in your main hand at the moment of the kill.

Feedback / Issues

Found a bug or have an idea for a feature (per-weapon leaderboards, decay on death, a max cap)? Leave a comment or open an issue — happy to keep improving this.