The present study is an extended replication of our first study about conspiracy theories (CTs) and the Need for Cognition (NfC): https://doi.org/10.17605/OSF.IO/PS5HE. We will attempt to replicate the finding that individuals with a moderate NfC are most likely to believe in CTs. Compared to our first study, we will change the dependent variable in order to replicate the effect with a set of different CTs. Furthermore, we will test fluid intelligence as a potential moderator of the NfC effects. We have argued that NfC determines the tencendy to engange in thinking about CTs. A moderate NfC was expected to result in the highest likelihood to believe in CTs because recipients of a potentially conspiratorial message very low in NfC would not engage in conspiratorial thinking at all, recipients with a very high NfC would discard it. Recipients with a moderate NfC however, would show a sufficient engagement to consider a conspiracy theory valid but not enough to find its flaws. Fluid intelligence could moderate this effect as it might change what degree of cognitive investment was necessary to (1) find conspiratorial narratives and (2) be able to discard them. Specifically, someone with a very high (vs. lower) fluid intelligence may not need as much of a cognitive investment in order to find flaws with a given narrative. On the other side of the coin, someone with a lower fluid intelligence may have to invest more cognitive effort to achieve similar results. Finally, we will also include the relevance of CTs as a specific quality of CTs which may affect results. This, however, will only be explored without specific hypotheses attached. For this study, data is collected using a shared online procedure with this study (the “relevant CT” study): https://doi.org/10.17605/OSF.IO/HSQZG. That is, participants answer all included items, but some are analyzed only for this study, whereas others are analyzed only for the “relevant CT” study (specified below).