Hello hai to every one I want to make the characters in a game world react has real world characters.Example going to job,waiting for bus,driving cars,teasing others,fighting with others.Some one please guide me.I don't know where to begin and which algorithms suitable for this. --Rajesh--

This Gamasutra article about activities will give you some ideas.

If you are completely lost, perhaps you can start with a more introductory-level material: Try reading Mat Buckland's "Programming Game AI by Example".

Thank you alvora

Can any one tell me what are the possible things for do crowd simulation

If I were you I suppose I'd build a behaviour pattern that would apply to every character in the crowd. Could you be a little bit more specific on what exactly you want to do? A crowd of enemy characters or a crowd of town people attending some outdoor activity? There are different approaches on how to solve this issue, at least from my point of view...

i need crowd of town peoples attending outdoor activities.Exactly behaviour pattern thank you for reply hazard org

I'm glad I could help out ;) If you have further questions please ask.

hazard
i want to know what are the possible step by step implentation(ex: A*,steering,etc..) for get that crowd simulation
If know help me please
Thanks in advance

Take a look at OpenSter, it has some nice stuff about steering behaviors. Also look at http://www.red3d.com/cwr/steer/, there is some demos for crowd simulation.

What you've mentioned are pathfinding algorithms. That makes your character go from point A to point B following an optimal path, avoiding obstacles on the way. But I suppose you would need more than that. Ussually AI programming isn't very generic, I cannot give you a step by step implementation method as I don't have any details on your game.

You can have a crowd of people visiting some places on the map (exploring a museum for example), a crowd of characters that would react depending on what the player does or distance between player and them.

I would really need a detailed description on what you want to do in order to give you a step by step solution. Take a look on this thread. It describes AI for a pack of zombies, attacking the player once he gets in their line of sight. But if your crowd is just visiting places on the map, moves randomly around or just stays in one place, the way you implement the AI would be completely different, or most of it.

If you want to have a general idea on simulating crowds read this. Also check gamedev's resources for guidance.