Selfmates with active white king 5

1...Rxc3 a 2.Se5+ A Sdxe5#
1...bxc3 b 2.Rf2+ B Sdxf2#

1.Kd5! th. 2.Qf6+ Sf4#
1...Rxc3 a 2.Rf2+ B Sdxf2#
1...bxc3 b 2.Se5+ A Sdxe5#
1...Rxc2 2.Qxd3+ Rxd3#

Very thematical key moves wK from one masked battery line to another. If capture of wQ by Black pins wSc4, White can safely force pin mate by Rf2+, while after opening indirect line, the mate must be forced by knight check. Precise logic of reciprocal change - compare to another s#2 by Milan Vukcevich with a key by wK!

By the way, this selfmate made it into Album FIDE 1974-76.

1.Ke1! zz
1...R~ 2.d3+ Sd2 3.Rxc7+ Bc5#
1...c6 2.Qc3+ Kb1 3.Rb7+ Bb6#
1...c5! 2.d4+ Kd3 3.dxc5+ Bd4#

Would you expect a key by wK here? And that it leads to a zugzwang position?!?

... but that's it! In fact, Black is left only with two random moves by rook and pawn, and then with correction by pawn.

1.Kd1! th. 2.Se3+ dxe3 3.Se5+ Sxe5#
1...Rg4 2.Se5+ Sxe5 3.Rxd4+ Rxd4#
1...Sg4 2.Rxd4+ Sxd4 3.Se3+ Sxe3#

I don't like the way of hiding the wK king down on the first row. However the content is not bad - we can find the cycle of 3 white moves based on the battery transformation.

1.Ka5! zz
1...Sf~ 2.Se3+ A Bxe3 3.Qb7+ B Kc4+ 4.Qb5+ Qxb5#
1...Se7! 2.fxe7 Kc4 3.Se3+ Bxe3+ 4.Qb5+ Qxb5#
     2...B~ 3.Qb7+ Kc4+ 4.Qb5+ Qxb5#
1...B~ 2.Qb7+ B Kc4 3.Rdxd4+ C Sxd4+ 4.Qb5+ Qxb5#
1...Be3!, Bxf6! 2.S(x)e3+ Sxe3 3.Qb7+ Kc4+ 4.Qb5+ Qxb5#
1...Kc4 2.Rdxd4+ C Sxd4 3.Se3+ A Bxe3+ 4.Qb5+ Qxb5#

The key brings wK into the prospective fire of the third-batery. However the battery is guarded more times by White, that's why there is the same final move in all the variations, attracting the bQ nearer, where she remains not under the fire. 2nd and 3rd white moves are cycled after random moves of Black pieces, after corrections White play must be, of course, slightly modified.

Another selfmate from this set that entered Album FIDE, in this case for period 1980-1982!

1.Ke8? th. 2.Rf8 th. 3.Sxc7+ Sxc7#
1...bxc5 2.Rf8 th. 3.Sxc7+ Sxc7#, 2...Sb6 3.Bd5+ Sxd5 4.Sxc7+ Sxc7#
1...Kf6!

1.Rg8! zz
1...bxc5 2.Sxc5+ Kf6 3.Re8 Sb6 4.Sd7+ Sxd7#
1...Kf6 2.Re8 bxc5 3.Sxc5 Sb6 4.Sd7+ Sxd7#

Unusual way of forcing the chameleon echo - in the try and in the solution.

1.Kb8! Kd6 2.Se5+ Kxe5 3.Sf6+ Sc5 4.Re8+ Kd6 5.Qg3+ Kc6 6.Rc8+ Kb6 7.Sd7+ Sxd7#

1.Ka6! Kd6 2.Ra7 Kc6 3.Sc3 Kd6 4.Sb6+ Kc6 5.Rc8+ Kd6 6.Sb5+ Ke5 7.Rc5+ Sxc5#


And this is another less usual form of selfmates with model mates - multiple solutions. In this case both keys are made by wK and the mates aren't the same, thus no echo.