AccountShield

The account-integrity layer your network is missing. Every network loses time to the same enemy: alt accounts. Ban evasion, alt-farming the economy, reward abuse and raid bots. AccountShield fingerprints every login and scores it against every account it has ever seen - the higher the score, the more likely it is the same person.

No database. No external services. Plain YAML next to the plugin.

What it catches

• Alt accounts - ranked matches with scores and human-readable reasons.
• Ban evasion - a login linked to a banned account is blocked at the earliest point, and re-checked after join with the fuller fingerprint.
• Raid bots / join floods - a sliding window per network range stops the classic "100 bots from one VPS range" raid before it reaches your server list.
• Alt-farming - know when several accounts that share a fingerprint are active at once.

How the fingerprint works

For each account it records the IP and a coarse range (/24 IPv4, /64 IPv6), the client brand, locale and stable client settings (skin parts, main hand, chat options...), the client's mod/plugin channel set, and the username.

Signals are weighted and summed (capped at 100):

Signal	Weight
Same exact IP	45
Identical client fingerprint	30
Matching mod set (>= 80% overlap)	20
Similar username	15
Same range (/24, /64)	12
Recently active from same range	10
Same locale	3

A shared IP alone will not link two accounts - households are handled with /accountshield trust <a> <b>.

Commands

Command	Description
/alts <player>	Ranked alt matches with scores and reasons
/accountshield info <player>	Everything stored for an account
/accountshield ban / unban	Manage bans
/accountshield trust / untrust	Whitelist accounts you know are different people
/accountshield watch <player>	Login alert
/accountshield list	Counts + watchlist

Aliases: /ashield, /as, /shield.

Alerts

In-game to staff, to console, and optionally to a Discord webhook.

Configuration

Thresholds, every signal weight, name/mod similarity, ban-evasion action (deny / kick / alert), raid window and limits, vanilla-ban respect and the webhook are all in config.yml.

Honest limits

Detection is heuristic. A VPN changes the IP signal; a fresh client changes the fingerprint. AccountShield raises the cost of alting and catches the careless majority - it is not magic.