The situation for the knight and iron general, which promote to pieces that do not keep their old moves, is unclear. Since there could be a reason to defer their promotion, it is possible that they receive a second chance to promote at the far rank on a non-capture, as in chu shogi. (In chu shogi, this provision applies to pawns, which are not completely upward compatible with the gold generals they promote to because of the rules against trading lions.) This second chance, if it exists, can likewise be declined, leaving the knight or iron general as an immobile "dead piece" (死に駒). However, this is uncertain, because it is not clear when the rule of pawn promotion was added to chu shogi (before or after the invention of tenjiku shogi), and because the Edo-era sources have numerous lacunae in the rules for the variants other than sho shogi and chu shogi.