Invasion theory suggests evolutionary and ecological processes allow invasive plant species to colonize native communities. Abiotic and biotic conditions in the environment (e.g., climate and competition with other plant species, respectively) will either decrease or increase invasion success, yet a synthesis of empirical research has not documented this phenomenon for any one invasive plant species. Further, current regional distribution models for invasive plant species rarely consider biotic interactions, instead focusing primarily on abiotic conditions. Thus, the relative importance of biotic interactions vs. abiotic limitations in shaping regional distributions is unknown. Here, new insight is provided related to invasion theory by identifying extreme weather, plant fitness and resident community as three broadly defined factors governing the invasion process. An invasion-factor framework is created from which conceptual models are developed using empirical studies published in the literature for three different and commonly occurring invasive plant species. This approach is the first to combine and synthesize the factors affecting the invasion process under a unifying framework to assess theoretical understanding and identify knowledge gaps, including predictive modelling, and perhaps guide future research.