We want to program a small minigame where we need a lot of icons for all kind of things (like in "Alchemy"). We looked through some free vector graphics pages, like http://www.freepik.com/, but they all state some vague instructions where and where-not to use the images.

For example this site writes

• For both personal and commercial projects and to modify it.

but on the other hand:

• Include FreePik Contents in an online or offline database or file.

Which sounds contradictionary, you need to store it in a file to modify it.

How can we get sure, that images that we use from such sites are really free to use on attribution and we don't get any problems later?

How should the licences look like, so we can be sure to get no problems later,if we use free icons from there?

We want to program a small minigame where we need a lot of icons for all kind of things (like in "Alchemy"). We looked through some free vector graphics pages, like http://www.freepik.com/, but they all state some vague instructions where and where-not to use the images.

For example this site writes

• For both personal and commercial projects and to modify it.

but on the other hand:

• Include FreePik Contents in an online or offline database or file.

Which sounds contradictionary, you need to store it in a file to modify it.

How can we get sure, that images that we use from such sites are really free to use on attribution and we don't get any problems later?

How should the licences look like, so we can be sure to get no problems later,if we use free icons from there?

We want to program a small minigame where we need a lot of icons for all kind of things (like in "Alchemy"). We looked through some free vector graphics pages, like http://www.freepik.com/, but they all state some vague instructions where and where-not to use the images.

For example this site writes

• For both personal and commercial projects and to modify it.

but on the other hand:

• Include FreePik Contents in an online or offline database or file.

Which sounds contradictionary, you need to store it in a file to modify it.

How can we get sure, that images that we use from such sites are really free to use on attribution and we don't get any problems later?

We want to program a small minigame where we need a lot of icons for all kind of things (like in "Alchemy"). We looked through some free vector graphics pages, like http://www.freepik.com/, but they all state some vague instructions where and where-not to use the images.

For example this site writes

• For both personal and commercial projects and to modify it.

but on the other hand:

• Include FreePik Contents in an online or offline database or file.

Which sounds contradictionary, you need to store it in a file to modify it.

How can we get sure, that images that we use from such sites are really free to use on attribution and we don't get any problems later?

How should the licences look like, so we can be sure to get no problems later,if we use free icons from there?