How to update a lua script from 2.6 to 3.0

This document describes how to convert freeciv-2.6 compatible lua script to one compatible with freeciv-3.0. Please check these carefully to avoid your script mis-behaving, maybe in some rarely reached special case. These are changes to scripting API requiring special attention. Additions to the API that do not affect old scripts are not listed.
==Turn number==
game.turn and turn_started signal have been deprecated. Use game.current_turn and turn_begin signal instead.
== See also ==
Category:Event scripting