INDIANAPOLIS — Once again an international throng of gaming enthusiasts will descend on the Indiana Convention Center on Thursday through Sunday for the 41st year of GenCon.

The convention started in Lake Geneva , Wis., which is why it carries its name. But it has blossomed into an event known worldwide within the genre of gaming.

Reasonable estimates are that about 85,000 people will attend the four-day run. Most are gamers, the people who buy the games. But many are retailers trying to stay ahead of the curve of new products and some are industry professionals trying to get some attention in a crowded marketplace during a poor economic time.

Some of those companies offer demos of products. Some run large tournaments for their fans with prizes that normally aren’t available for purchase. There are over 6,000 events scheduled for the convention’s run.

The Settlers of Catan World Championship will culminate in a big board tournament at this year’s GenCon.

A large percentage of the gaming goes on well past the 5 p.m. closing of the main exhibit hall. In fact, some gaming can be found at the Convention Center for 24 hours each day.

Virtually every type of non-gambling game is offered. There are trading card games, role playing games, card games, board games, miniatures along with video and computer games.

There is a special place on the exhibit hall floor for games that have broad appeal and can be played by large groups and entire families.

There are also art shows, celebrities signing autographs as well as special video media presentations and movies. Some of the big new products being shown for the first time at the show include:

— Upper Deck is introducing the Yu-Gi-Oh 5D trading card game based on the anime TV series, which will premiere on TV next month.

— Upper Deck will also be unveiling its soon-to-be-released World of Warcraft miniatures game.

— Fantasy Flight Games will offer new packaging and starting point for its popular A Game of Thrones trading card game.

— Playroom Entertainment offers a limited number of copies of its new game Killer Bunnies and the Journey to Jupiter. Demos will be offered the entire show.

— Privateer Press will be showing its new miniatures game Monsterapocalypse.

·— Steve Jackson Games will give fans a first look at Munchkin Booty, the next addition to the popular Munchkin line, this time with a pirate theme.