Bethesda has said there will "definitely" be no developer tools shipped with the PC version of Fallout 3.
But it remains a possibility for the future, unlike on consoles where there are too many "barriers" to overcome.
"It will definitely not be included on the disk," said Todd Howard in a fan interview on the Bethesda forum. "If and when one is available it will be a free download. I wish I could promise that an editor will be coming and when, but I can't.
"As far as consoles go, that's not happening for this game and user content. It's something we keep talking about with Microsoft and Sony, but there are a lot of barriers there right now, from delivery to security.
"We'd love to see that happen," Howward continued. "I'd love to see Oblivion content created by PC users available to all platforms, because the data is the same, most of them would pretty much 'work' right away."
Howard explained that quite a lot of the mechanics in Fallout 3 are similar to Oblivion, but tweaked and streamlined for a less expansive and more focused story - with many more outcomes.
There should be a full skill list in a few weeks, he promised, before explaining that Traits from the previous Fallout games have been rolled into Perks. There are around 100 of these and you get to pick one each time you level up in Fallout 3.
There are 20 levels in total, so theoretically there are 19 skill decisions to make. Howard said it was "important" not to let players see everything in one play through, and to make customisation choices hard.
Fallout 3 is due for PC, Xbox 360 and PS3 this autumn. Pop over to our Fallout 3 gamepage to find out more.