在輻射:新維加斯中，亨利博士擁有隱身小子Mark.II的原型機，Experimental even before the Great War, 他試圖通過研究來重現這一技術，解決隱身小子給夜行者帶來的問題。However upon asking Lily Bowen, a friendly nightkin to assist with the experiment he is soon interrupted by Keene who demands the schematics so he and his band of nightkin can modify existing Stealth Boys to mark 2. The Courier then has a choice between talking Keene out of it, killing him or giving him the schematics.
長期使用隱身小子have been found to have unpleasant mental side-effects，主要為焦慮，莫名其妙的妄想與偏執，甚至情緒波動劇烈以及精神分裂，這些癥狀在長期使用隱身小子後才表現出來（遊戲中玩家可以自由使用隱身小子而不用承受不良效果），although they appear only after a few uses when used by Nightkin. As Nightkin were originally The Master's elite stealth troops, 幾乎每一個夜行者都使用隱身小子，這也導致了他們每一個都患有隱形小子症。Their mental problems vary, 但最普遍的還是假想出一個不存在的同伴/分裂出第二人格(similar to Dissociative Identity Disorder)。代表人物有塔比瑟，Davison，莉莉奶奶和狗與神。使用隱身小子有很大可能是上癮的，表現為一段時間不使用潛行小子後他們會變得暴躁，攻擊性更強，並且討厭被人看到或者盯著看。
Stealth Boys can be found in Fallout, Fallout 3, Fallout: New Vegas, and Fallout 4, although it is mentioned in Fallout 2 and its description is present in Fallout Tactics files. 隱形小子的設定直到范布倫計劃時才被確定下來, where it was spelled as StealthBoy to prevent it from being confused with the "Stealth Boy" playing style. It was going to appear in the canceled 輻射:鋼鐵兄弟會2，以隱身小妞之名，實際上只被一名女性使用者Scarlet使用。Stealth Girl later became a reference used in Fallout: New Vegas, as the companion perk given by Lily Bowen, a female nightkin, the perk provides a 200% increase in Stealth Boy duration.