There are some special dice for the Alien RPG, some simple six-sided custom printed dice that really add to the atmosphere of the game.
Are they needed to play the game? To be honest; no, not at all. Unlike the custom dice with special symbols specifically made for other games - making them essential for play - these are just 16mm six-sided dice with a single number changed with either a target for a six or a facehugger for a 1.
There are two sets, the Base Dice Set and the Stress Dice Set.
The Base Dice Set is coloured black and have a target where the 6 should be to represent successs when rolling a standard action.
The Stress Dice Set are yellow, with a facehugger where the 1 should be to represent a failed Stress roll.
Having different coloured dice to represent the different kinds of rolls that are made is a neat little idea, and having a target appear is a cause for celebration whereas the facehugger can lead to groans across the table. It does add a bit of atmosphere and seeing the symbols come up results in an immediate emotional reaction, but this fades after some use and then they are regarded as regular dice.
And that's my issue with these - they're great for the collector or the completist and really do add to the game's aesthetic, but at the end of the day they are just six-sided dice and the only difference is the symbols. If you buy the rulebook as it is then you really don't need them, but they are a fun addition to the game and collectors will get a lot of fun out of them. The gimmick and the price may turn a lot of people off.
Me, as a collector? I like them. And they're going to look great in the custom dice bag I've ordered with the open Alien egg on the fabric.