is where one with no right, no spark of right, enters into vacant possession, possessed  neither corpore nor animo, as into an hereditas iacens before it had been taken up by  the heir,1 or by the chief lord by reason of wardship or as his escheat, if there are no  heirs, or where, after the death of [a tenant], one puts himself in seisin before the  tenement has come to him to whom it ought to come by a fine levied, or the modus of  a gift, where succession can play no part, or where, after the death of one who holds  for life the tenement ought to revert to the owner. [What possession must be called  vacant and what not, may be seen clearly enough above in the title on the acquisition  of possession.]2 When one having no right has so intruded himself and does not admit  the heir or the chief lord, as was said above, or him to whom the tenement ought to  revert by fine levied, by the modus of the gift, or as an escheat on the failure of heirs  or the commission of felony, or in any other way whatever, help is afforded those3 to  whom the tenement ought to revert, in several ways, depending on their several cases,  by the following writs. If it ought to revert to the chief lord as his escheat because one  enfeoffed to him and the heirs of his body issuing has died without such heir, the  writ is this:
Of land which ought to revert for various reasons as an escheat to a chief lord.
 The king to the sheriff, greeting. Put A. by gage and safe pledges that he be before  etc. to answer B. as to why he intruded himself into so much land with the appurtenances  in such a vill which C. held of the said B., and of which the same C. was seised  on the day he died, and which ought to revert to the same B. as to the chief lord of  that fee since the aforesaid C. died without an heir of his body. And have etc. Witness  etc.
If one has intruded himself into land which ought to revert.
 There is another form of the same writ, where one who is not heir has intruded himself  into land as though he were heir, on the seisin of the chief lord, which ought to remain  in his hand until the true heir has come to do to him what of right he ought to do. In  that case the writ is this:
By what warrant he intruded.
 [The king to the sheriff etc. Put A. etc.] to answer [B.] by what warrant he intruded  himself into so much land belonging to the fee of the said B., which the said B. had  taken into his hand until the true heir should come to do to him what of right he  ought to do, as