The first edition of Aftermath (1980) was produced by Phoenix Games. The few of these early Phoenix sets that I’ve seen have Fantasy Games Unlimited stickers over the PG company logo.

The lid art is different from the FGU sets that would follow: The man is drawn slightly differently, and the woman is missing. The contents are identical to the later (1981) edition.

I’ve seen plenty of examples of an alternate 1981 version with white-covered books (as opposed to the more usual yellow covers).

Later appears a combined Paperback edition, a reprint of the the classic FGU set.

Aftermath! Roleplaying Game

1980, 1981 … Robert Charrette & Paul Hume … Phoenix Games / Fantasy Games Unlimited (FGU) 4000

Aftermath RPG items in the shop

The Aftermath RPG product line cataloged at my reference site

EDIT May 24, 2020

Aftermath lot
A later FGU Aftermath set with accompanying module adventures
Aftermath d20 w TSR d20
Some Aftermath sets sold with tiny d20 (numbered 0-9 twice) – from Gamescience I think. This one is white and the numbers are not crayoned. Here it is shown with a TSR d20 of the time (ca. 1981) for scale – the TSR d20’s were kinda small themselves.

Aftermath RPG items in the shop

See also:

CITY STATE: A drop-in Chicago Sourcebook for your T2000 campaign

Early print of Aftermath! Magic!

GAMMA WORLD 1st ed (1978-82): The Original Post-Apoc RPG

Omega War: Science Fantasy Adventure Game (1983)