Well, if you want to use threads, you can get a more recent perl with better thread support, or take a look at forks - it emulates the newer thread API using fork().

OTOH, you might use something like POE to get callbacks into 1 process/thread whenever an event is triggered. You could maybe even get away with using alarm() to trigger your own timeouts if you want to get that low-level.

If you are using Tk or some other GUI toolkit, most of them also have some kind of event handling to accomodate this kind of thing (see Tk::Eventloop for instance)

One other strategy that might help if you run multiple processes already (say, for instance you're running the game from CGI or mod_perl) is to use a shared data storage (like a relational database), so all data can be shared "automatically" as long as you check for updates periodically. Other options here are IPC::ShareLite and Cache::Cache.

Have fun figuring out which one you like :-)

Joost.