Research tree....

[Recruit69]

I am not entirely sure but on TFTD, I complete my first mission, I get artifacts, but i can only research a select few before unlocking more research items in your inventory... i.e. Plasma Pistol, ==> Plasma Rifle ==> Heavy Plasma

OpenXcom EU.... I complete my first mission, I get artifacts, but i can research ANY item, so can start research Heavy alien weapons immediately? Is this right? Or is it a bug? Or is it something I've missed?? (Never played original EU, just original TFTD!)

[SupSuper]

TFTD's tree is much more complex than UFO's, however in both games you can research any alien weapon you pickup immediately.
https://www.ufopaedia.org/index.php?title=Research_Trees
https://www.ufopaedia.org/index.php?title=Research_(TFTD)