When a empire goes inactive, and can not (or will not) be replaced with a real player, I take over control of that empire. This typically has the following effects:
Political status: I don't change them unless you shoot first (except in rare circumstances). I also typically ignore forwarded messages.
Tech advancement: I will do some, but generally don't do it until planet defenses are sufficient. Note: since NPC's get all GM generated notices, they will make use of the various tech levels published to determine if they need to do tech research.
Economics: I will max out planets, and possibly colonize planets that have col in orbit or en-route. Nearby uninhabited worlds may be colonized as well.
Ship production: generally speaking, warships are pulled back to inhabited systems. All ships are upgraded to current tech (within reason). All systems are given some sort of defenses, time permitting. Typically a system only has what started there, and what it can build. I will build general defenses, not ones that are optimized against any player(s) (unless I can do it from looking at the inactive player's turn report). The longer an NPC is left alone to grow, the more I will move around units to balance out defenses.
Warfare: If you attack an empire I'm playing under these rules, and they have probes over your systems (or did at the begining of the turn), they may counter-attack; particularily if the systems are lightly defended....
The general attempt of the above is to create a player that is not trivial to knock off (ala the inactive since turn 1 type), nor will it take unfair advantage of knowledge that it doesn't have but the GM does. I usually only spend 5 minutes or less on a player's orders.
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