There are a few categories that consistently lead to permanent punishments in 'Old School RuneScape', and they usually fall under cheating, real-money involvement, or account crimes. Botting and any kind of automated play is the archetypal instant-red-zone behavior — Jagex treats automation as a direct threat to the game's integrity, and accounts caught botting often get permanently banned after detection. Real-world trading (RWT) — buying or selling in-game currency, items, or accounts for real money — is another big one that commonly results in permanent action.
Account theft, account sales, and using
stolen payment methods also trigger severe sanctions. If an account is obtained or used through unauthorized access, or if purchases on the account are reversed (chargebacks), Jagex can and will permanently disable those accounts. Exploiting dupes or major bugs and then converting those gains into real-money benefits puts you in the same category. While scamming or griefing might sometimes receive temporary penalties, large-scale, repeat, or monetized scamming tends to escalate.
To keep things practical: avoid third-party services that promise gains, don't buy gold or accounts, protect your credentials with an authenticator, and never exploit bugs for profit. I've seen too many friends learn the hard way; protecting your account is both smart and ultimately more fun.