Iphone

I have an eleven year old child that spends hours and hours playing SIMS2, and who dreams of growing up to write games like that.
I haven't learned about SIMS2 and I do not know how much flexibility SIMS2 offers the player. My sense is that the eleven y.o. would like to operate software that lets game elements to be created, situated, and interactivity defined. I guess he's looking for a virtual reality game where the operator creates virtual reality games!
Suggestions???

Iphone

Gaming industry is a multi-disciplinary world. Artists for scenario/backgrounds, world and environment creators (semi-gods, I think), lightning specialists, character creators, character modelers, animators, writers, programming developers, art directors, designers, game conception, film makers for openings (some games have great films to create the climate for the game), are some of the specilized jobs around.

As at 11 yo the children didn't developed the abstract and math reasoning needed to understand and create algorithms, it would be a good starting point the creation of characters (human, humanoids, animals) and props (objects in general, furniture, etc) in a interactive way.

You may want try to leverage his/her talent, first in discovering which are is more interesting and attractive.

For 3D creation, modeling and animation, the top programs are 3Dmax, Maya, Cinema 4D. They are expensive and their use is quite complicated. The inexpensive trueSpace (3D Modeling Software - trueSpace) can be a good start. Version 4.3 is in promotion for 20 dollars and version 3.2 is free. This SW has a lot of models, imports a number of models from the internet. Animation is not an easy task, but there is some simple things for an 11 yo child to do. It is also a starting point to 3D skill development and programming concepts.

For animation of human characters, take a look at Poser. Full features of Poser 7 are at http://www.e-frontier.com/article/articleview/1737/1/738 . It is expensive for just trying. There are older versions of Poser at ebay. Version 5 is a great program, probably your child will spent a time enjoying its features.

For terrain modeling and animation, VistaPro is a very good program. It permits to navigate through Yosemite, Grand Canyon, or even Mars (http://www.vendornation.com/*ws4d-db-query-QuickShow?mrx001), where you can fly around. Very funny. You may create interesting video films. It also helps to develop the three dimensional perception and creation skills. VistaPro 4 is sold at http://www.vendornation.com/*ws4d-db-query-QuickShow?vp001
Vue is another good option http://www.e-frontier.com/go/products/vueeasel

Actually these tools aren't for children, but if yours is motivated (and you too) would enjoy another side of computing visual arts and gaming, not as a consumer, but as a creator instead.

My daughter is now 17 yo, also likes SIMS and is doing for her 2nd course on animation. She has hand on computers from the 4, with simple educational games and some from Disney. Now uses Photoshop as a pro (hum... pardon me... she's my baby, eh?).

The only care is to avoid a shock and the disappointment for inverse effect if the required skills are much higher to your child (actually a teenager...) Take it slowly, in the right pace.