It really doesn't take up too much of the computers time just to test for a collision. The simple way to do the collision testing would be to give each tile a certain id. Such as 0 if the player can't walk on it, and a 1 if they can.

How to check for collision in a game like Zelda, Chaos Engine etc ? Is every visible object a rectangle and when the player moves it check to see if the rectangles crosses? If the gameplan is a labyrint seen from above with many, many walls it must bee tough to write and demanding for the computer to update.

Collision detection is different depending on how your game is designed. If it is a 2d, or some for of tile based game, than yes use tile IDs.

3D collision detection is a little different because you need to choose how accurate you want to be.

If you have say a person one way is to use a bounding box, which is basicly a box fit right around the person and anything that fits in the box is considered a collision.

Though this collision detection is fast it is not accurate. Say the person has thier arms stretched out and the object colliding was underneath them, you will still get a collision because of the box around the person will catch it. (This is easier to show , than write)

So you have a choice, you can use boinding boxes for each part of a person or a more accurate, polytope.

This is basicly a very simplified version of the objects 3D mesh. You can than use this for collisions with more accuracy.

Gary