The No-Tampering Condition is often taken to derive effects of the Extension Condition and the Inclusiveness Condition; however there is no definition of the No-Tampering Condition in Chomsky’s articles that fully captures effects of both conditions. This paper proposes a new condition which in connection with other properties of the proposed system not only derives effects of the Extension Condition and the Inclusiveness Condition, but also has several welcome consequences. It is shown that the proposed system does not need to employ null phase heads and the Phase Impenetrability Condition and that it supports the copy theory of movement. The proposal is couched in a derivational model where every operation Merge produces a phase which can be transferred to interfaces.