# TD Grid Placement Help

**URL:** https://forum.kirupa.com/t/td-grid-placement-help/230520
**Category:** programming
**Created:** [June 26, 2007, 10:01pm UTC](https://forum.kirupa.com/t/td-grid-placement-help/230520 "2007-06-26T22:01:08Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Saidon](https://avatars.discourse-cdn.com/v4/letter/s/e99b99/32.png) [@Saidon](https://forum.kirupa.com/u/Saidon)
#### Post date: [June 26, 2007, 10:01pm UTC](https://forum.kirupa.com/t/td-grid-placement-help/230520/1 "2007-06-26T22:01:08Z")

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Hi, I’m trying to make a tower defense game not unlike the one at [www.handdrawngames.com](http://www.handdrawngames.com) (Desktop Tower Defense). All was going well until I had to figure out how to build the towers so that they “lock” to a grid. My towers are 40px by 40px and I want to build them on a grid that is made up of 20px by 20px squares so that they can be built with more variety.

A quick break down of where I need help:

1. How to select the tower I want to build and then place it by clicking on the grid

2. How to have the towers lock to a grid half the size of the towers themselves

Any advice would be greatly appreciated, I’ve been googling this for hours and wasn’t able to figure it out.