diff --git a/bridges.c b/bridges.c
index e96861e..7043950 100644
--- a/bridges.c
+++ b/bridges.c
@@ -2141,15 +2141,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3294,8 +3285,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/cube.c b/cube.c
index 46bd745..0512746 100644
--- a/cube.c
+++ b/cube.c
@@ -1038,15 +1038,6 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1771,8 +1762,8 @@ const struct game thegame = {
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/devel.but b/devel.but
index 6496aef..9ce8eee 100644
--- a/devel.but
+++ b/devel.but
@@ -885,6 +885,9 @@ user could edit the save file by hand... But if the user is \e{that}
 determined to cheat, they could just as easily modify the game's
 source.)
 
+The \cw{encode_ui()} function is optional.  If a back-end doesn't need
+this function it can just set the pointer to \cw{NULL}.
+
 \S{backend-decode-ui} \cw{decode_ui()}
 
 \c void (*decode_ui)(game_ui *ui, const char *encoding);
@@ -896,6 +899,9 @@ the best it can, which might just mean not changing the \c{game_ui}
 structure at all.  This might happen if a save file is corrupted, or
 simply from a newer version that encodes more \c{game_ui} data.
 
+Like \cw{encode_ui()}, \cw{decode_ui()} is optional.  If a back-end
+doesn't need this function it can just set the pointer to \cw{NULL}.
+
 \S{backend-changed-state} \cw{changed_state()}
 
 \c void (*changed_state)(game_ui *ui, const game_state *oldstate,
diff --git a/dominosa.c b/dominosa.c
index e529376..eba9465 100644
--- a/dominosa.c
+++ b/dominosa.c
@@ -2727,15 +2727,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3446,8 +3437,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/fifteen.c b/fifteen.c
index f453d59..5d01aa2 100644
--- a/fifteen.c
+++ b/fifteen.c
@@ -458,15 +458,6 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1105,8 +1096,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/filling.c b/filling.c
index 0c2d292..7e74e2d 100644
--- a/filling.c
+++ b/filling.c
@@ -1413,15 +1413,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2179,8 +2170,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
diff --git a/flip.c b/flip.c
index 267e5a2..d989a28 100644
--- a/flip.c
+++ b/flip.c
@@ -926,15 +926,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1348,8 +1339,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/flood.c b/flood.c
index c5fc10c..f1c40f1 100644
--- a/flood.c
+++ b/flood.c
@@ -790,15 +790,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1376,8 +1367,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/galaxies.c b/galaxies.c
index 0b10b59..beb53fe 100644
--- a/galaxies.c
+++ b/galaxies.c
@@ -2701,15 +2701,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -4137,8 +4128,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
 #ifdef EDITOR
diff --git a/keen.c b/keen.c
index baf8a43..cea8061 100644
--- a/keen.c
+++ b/keen.c
@@ -1544,15 +1544,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2488,8 +2479,8 @@ const struct game thegame = {
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
diff --git a/lightup.c b/lightup.c
index 35705a6..f60017f 100644
--- a/lightup.c
+++ b/lightup.c
@@ -1848,17 +1848,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    /* nothing to encode. */
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-    /* nothing to decode. */
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2343,8 +2332,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/loopy.c b/loopy.c
index bd37a5a..8f5a8a0 100644
--- a/loopy.c
+++ b/loopy.c
@@ -879,15 +879,6 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3681,8 +3672,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/magnets.c b/magnets.c
index 82d6ccd..45ebc83 100644
--- a/magnets.c
+++ b/magnets.c
@@ -1745,15 +1745,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2468,8 +2459,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/map.c b/map.c
index a9b2347..fff4486 100644
--- a/map.c
+++ b/map.c
@@ -2302,15 +2302,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3267,8 +3258,8 @@ const struct game thegame = {
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/midend.c b/midend.c
index e66d15a..2e49e8d 100644
--- a/midend.c
+++ b/midend.c
@@ -2204,7 +2204,7 @@ void midend_serialise(midend *me,
     /*
      * Any required serialisation of the game_ui.
      */
-    if (me->ui) {
+    if (me->ui && me->ourgame->encode_ui) {
         char *s = me->ourgame->encode_ui(me->ui);
         if (s) {
             wr("UI", s);
@@ -2541,7 +2541,7 @@ static const char *midend_deserialise_internal(
     }
 
     data.ui = me->ourgame->new_ui(data.states[0].state);
-    if (data.uistr)
+    if (data.uistr && me->ourgame->decode_ui)
         me->ourgame->decode_ui(data.ui, data.uistr);
 
     /*
diff --git a/mosaic.c b/mosaic.c
index 752caab..98e7077 100644
--- a/mosaic.c
+++ b/mosaic.c
@@ -1022,15 +1022,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1620,8 +1611,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/netslide.c b/netslide.c
index eab44a9..164bf9c 100644
--- a/netslide.c
+++ b/netslide.c
@@ -983,15 +983,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 /* ----------------------------------------------------------------------
  * Process a move.
  */
@@ -1869,8 +1860,8 @@ const struct game thegame = {
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/nullgame.c b/nullgame.c
index 9c5f868..aa5ca99 100644
--- a/nullgame.c
+++ b/nullgame.c
@@ -121,15 +121,6 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -248,8 +239,8 @@ const struct game thegame = {
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/palisade.c b/palisade.c
index ec9ddaf..458ce37 100644
--- a/palisade.c
+++ b/palisade.c
@@ -887,15 +887,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1388,8 +1379,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/pattern.c b/pattern.c
index fa6213e..4fd6753 100644
--- a/pattern.c
+++ b/pattern.c
@@ -1250,15 +1250,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2087,8 +2078,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/pearl.c b/pearl.c
index a54ae15..c668641 100644
--- a/pearl.c
+++ b/pearl.c
@@ -1878,15 +1878,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2729,8 +2720,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/pegs.c b/pegs.c
index 06a312d..7cd33e8 100644
--- a/pegs.c
+++ b/pegs.c
@@ -813,15 +813,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1372,8 +1363,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/range.c b/range.c
index 3e7b00c..8b1b602 100644
--- a/range.c
+++ b/range.c
@@ -1240,15 +1240,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static const char *current_key_label(const game_ui *ui,
                                      const game_state *state, int button)
 {
@@ -1831,8 +1822,8 @@ struct game const thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/rect.c b/rect.c
index bc7e179..00e84c4 100644
--- a/rect.c
+++ b/rect.c
@@ -2220,15 +2220,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void coord_round(float x, float y, int *xr, int *yr)
 {
     float xs, ys, xv, yv, dx, dy, dist;
@@ -3004,8 +2995,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/samegame.c b/samegame.c
index caa8141..d1f1f2e 100644
--- a/samegame.c
+++ b/samegame.c
@@ -1077,15 +1077,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void sel_clear(game_ui *ui, const game_state *state)
 {
     int i;
@@ -1677,8 +1668,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/signpost.c b/signpost.c
index 910de48..f568488 100644
--- a/signpost.c
+++ b/signpost.c
@@ -1410,15 +1410,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2293,8 +2284,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/singles.c b/singles.c
index 485529a..a977d10 100644
--- a/singles.c
+++ b/singles.c
@@ -1461,15 +1461,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1861,8 +1852,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/sixteen.c b/sixteen.c
index c540438..01fd6df 100644
--- a/sixteen.c
+++ b/sixteen.c
@@ -584,15 +584,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1202,8 +1193,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/slant.c b/slant.c
index 65f5329..13ba366 100644
--- a/slant.c
+++ b/slant.c
@@ -1595,15 +1595,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2186,8 +2177,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/solo.c b/solo.c
index 208c705..83bdeb8 100644
--- a/solo.c
+++ b/solo.c
@@ -4573,15 +4573,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -5639,8 +5630,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
diff --git a/tents.c b/tents.c
index 86b5245..9f904f9 100644
--- a/tents.c
+++ b/tents.c
@@ -1468,15 +1468,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2656,8 +2647,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/towers.c b/towers.c
index 04abed0..43d5f03 100644
--- a/towers.c
+++ b/towers.c
@@ -1177,15 +1177,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2063,8 +2054,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
diff --git a/tracks.c b/tracks.c
index ea48510..f4672d2 100644
--- a/tracks.c
+++ b/tracks.c
@@ -2033,15 +2033,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3056,8 +3047,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/twiddle.c b/twiddle.c
index c3b4764..626b621 100644
--- a/twiddle.c
+++ b/twiddle.c
@@ -632,15 +632,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1316,8 +1307,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/undead.c b/undead.c
index a1bd9fd..d4f0ee1 100644
--- a/undead.c
+++ b/undead.c
@@ -1661,16 +1661,6 @@ static void free_ui(game_ui *ui) {
     return;
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-    return;
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2796,8 +2786,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
diff --git a/unequal.c b/unequal.c
index 12cdd7c..f6ce50f 100644
--- a/unequal.c
+++ b/unequal.c
@@ -1454,15 +1454,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2163,8 +2154,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
diff --git a/unfinished/group.c b/unfinished/group.c
index bbac220..7a2ffe6 100644
--- a/unfinished/group.c
+++ b/unfinished/group.c
@@ -1272,15 +1272,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2332,8 +2323,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/unfinished/separate.c b/unfinished/separate.c
index d3423de..324a966 100644
--- a/unfinished/separate.c
+++ b/unfinished/separate.c
@@ -705,15 +705,6 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -845,8 +836,8 @@ const struct game thegame = {
     false, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/unfinished/slide.c b/unfinished/slide.c
index 115230f..fe573e8 100644
--- a/unfinished/slide.c
+++ b/unfinished/slide.c
@@ -1217,15 +1217,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2337,8 +2328,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/unfinished/sokoban.c b/unfinished/sokoban.c
index bef7d72..65d1fa6 100644
--- a/unfinished/sokoban.c
+++ b/unfinished/sokoban.c
@@ -927,15 +927,6 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1459,8 +1450,8 @@ const struct game thegame = {
     false, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
diff --git a/unruly.c b/unruly.c
index 4b48f16..a8df09a 100644
--- a/unruly.c
+++ b/unruly.c
@@ -1527,15 +1527,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2039,8 +2030,8 @@ const struct game thegame = {
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
diff --git a/untangle.c b/untangle.c
index 62d5897..85d8fc9 100644
--- a/untangle.c
+++ b/untangle.c
@@ -1055,15 +1055,6 @@ static void free_ui(game_ui *ui)
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1465,8 +1456,8 @@ const struct game thegame = {
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */