"Just install AMX Mod X" hides a real decision: which version? The differences between 1.8.2, 1.9, 1.10 and the 1.11 development line are not cosmetic — they change which natives you can call, which modules load, and whether a plugin someone else compiled will even run on your server. Here is what separates the branches and how to pick.
| Version | Status | In one line |
|---|---|---|
| 1.8.2 | Old, still widespread | The long-time default; stable but missing newer natives. |
| 1.9 | Stable | The safe modern default; adds natives 1.8.2 lacks. |
| 1.10 | Current stable | The current recommended release. |
| 1.11-dev | Development | Bleeding edge; not for production unless you need something in it. |
Each line added natives and module capabilities. The most-cited example: coloured chat printing. client_print_color — the native that prints team-coloured chat with ^x01/^x03/^x04 codes — exists from 1.9 onward, not in 1.8.2. A plugin that calls it will fail to compile on 1.8.2 and, if you download a pre-compiled build, may bad-load on a 1.8.2 server. This is why plugin pages specify a minimum AMXX version: if a plugin lists amxx_min 1.9, it is telling you it uses at least one native that does not exist in 1.8.2.
The subtler issue is binary compatibility of modules and plugins across branches. AMXX modules (the .so/.dll files providing fakemeta, hamsandwich, etc.) and the compiled .amxx plugins are built against a specific branch's interfaces. A plugin or module compiled for one branch can bad-load on another because the internal ABI changed between release lines. Symptoms you will see in amxx plugins:
amxx plugins // a mismatched plugin shows: // myplugin.amxx bad load
The fix is to compile the plugin against the branch you actually run, or download the build that matches your version — not to force a foreign binary. When you upgrade the core, upgrade the modules to the matching build too; a 1.10 core with leftover 1.8.2 modules is a reliable way to produce bad load lines.
Each AMXX version ships its own amxxpc compiler and its own set of include files. Compiling with the 1.9 compiler bakes in the 1.9 natives and interfaces; compiling the same source with the 1.10 compiler targets 1.10. This is exactly why a live compile service pins multiple toolchains — the correct binary depends on the target server's version. When in doubt, compile with the toolchain matching the server you will run it on.
Install guides per version: 1.8.2, 1.9, 1.10.
Moving between lines is not just swapping the core binary. A clean upgrade means replacing the AMXX core files, replacing every module with the matching-branch build, and recompiling any plugin you built yourself against the new compiler and includes. Third-party plugins you downloaded pre-compiled for the old branch should be re-downloaded in a build for the new one, or recompiled from their .sma. Your configs — plugins.ini, modules.ini, amxx.cfg — generally carry over, but new versions sometimes add cvars or change defaults worth reviewing. The single most common upgrade failure is leaving old modules in place: a 1.10 core will happily start but every plugin that touches a stale 1.8.2 module bad-loads. The full procedure for the most common jump is in upgrading 1.8.2 to 1.10. Do it on a test server first and confirm a clean amxx plugins output before touching production.
client_print_color. Modern plugins increasingly require 1.9+.From the server console:
amxx version meta list
amxx version prints the running AMX Mod X version and build; meta list confirms AMXX loaded under Metamod. Then run amxx plugins and scan for any bad load — those are your version/ABI mismatches. If you see them after an upgrade, replace those plugins and modules with builds matching your core version and reload the map.