Add different highlight for dangerous moves. Make colors clearer.

Moves into spaces which will yield to the opponent are highlighted with an
extra red inside border.

Also change colors to be consistent:

Yellow - action for both spaces and units
Blue - selected unit
White - highlight (both for tooltip and current battle/intercept space)

Clearer blue and red colors for supply lines.

RED

10 files changed, 152 insertions, 103 deletions

diff --git a/mountain-danger.svg b/mountain-danger.svg
new file mode 100644
index 0000000..fd9cb5d
--- /dev/null
+++ b/mountain-danger.svg
@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
+<path fill="none" stroke="#f00" stroke-width="8" d="m106.203 59.988-3.814 6.645-23.34-22.328L21.15 132h168.596L127.947 22.14l-21.744 37.848Z"/>
+<path fill="none" stroke="#ff0" stroke-width="8" d="M10 138 78 35l23 22 27-47 72 128Z"/>
+</svg>
diff --git a/mountain-highlight.svg b/mountain-highlight.svg
index c499ef5..0473bbd 100644
--- a/mountain-highlight.svg
+++ b/mountain-highlight.svg
@@ -2,7 +2,7 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
 <path
 	fill="none"
-	stroke="white"
-	stroke-width="10"
+	stroke="yellow"
+	stroke-width="8"
 	d="M 10 138 L 78 35 L 101 57 L 128 10 L 200 138 Z"/>
 </svg>
diff --git a/mountain-selected.svg b/mountain-selected.svg
index fb4dfca..3dd60fa 100644
--- a/mountain-selected.svg
+++ b/mountain-selected.svg
@@ -2,7 +2,7 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
 <path
 	fill="none"
-	stroke="crimson"
-	stroke-width="10"
+	stroke="white"
+	stroke-width="8"
 	d="M 10 138 L 78 35 L 101 57 L 128 10 L 200 138 Z"/>
 </svg>
diff --git a/mountain-supply-both.svg b/mountain-supply-both.svg
index e618244..9a63043 100644
--- a/mountain-supply-both.svg
+++ b/mountain-supply-both.svg
@@ -2,12 +2,12 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
 <path
 	fill="none"
-	stroke="#f0594e"
+	stroke="red"
 	stroke-width="10"
 	d="M 10 138 L 200 138 L 128 10 "/>
 <path
 	fill="none"
-	stroke="#0092d5"
+	stroke="blue"
 	stroke-width="10"
 	d="M 10 138 L 78 35 L 101 57 L 128 10"/>
 </svg>
diff --git a/mountain-supply-british.svg b/mountain-supply-british.svg
index 5808b63..22a60af 100644
--- a/mountain-supply-british.svg
+++ b/mountain-supply-british.svg
@@ -2,7 +2,7 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
 <path
 	fill="none"
-	stroke="#f0594e"
-	stroke-width="10"
+	stroke="red"
+	stroke-width="12"
 	d="M 10 138 L 200 138 L 128 10 "/>
 </svg>
diff --git a/mountain-supply-french.svg b/mountain-supply-french.svg
index 6f8ea17..f4e74d5 100644
--- a/mountain-supply-french.svg
+++ b/mountain-supply-french.svg
@@ -2,7 +2,7 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
 <path
 	fill="none"
-	stroke="#0092d5"
-	stroke-width="10"
+	stroke="blue"
+	stroke-width="12"
 	d="M 10 138 L 78 35 L 101 57 L 128 10"/>
 </svg>
diff --git a/mountain-tip.svg b/mountain-tip.svg
index 50a4aac..3dd60fa 100644
--- a/mountain-tip.svg
+++ b/mountain-tip.svg
@@ -2,8 +2,7 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="210" height="148">
 <path
 	fill="none"
-	stroke="yellow"
-	stroke-width="10"
-	stroke-dasharray="20 20"
+	stroke="white"
+	stroke-width="8"
 	d="M 10 138 L 78 35 L 101 57 L 128 10 L 200 138 Z"/>
 </svg>
diff --git a/play.css b/play.css
index 303af48..e59cd07 100644
--- a/play.css
+++ b/play.css
@@ -7,6 +7,11 @@ body.Britain header.your_turn { background-color: salmon; }
 #role_Britain, #log .h2.britain { background-color: #fcb; }
 aside { width: 220px; }
 
+:root {
+	--highlight-color: yellow;
+	--selected-color: blue;
+}
+
 .role_vp { float: right; }
 
 .checked::before { content: "\2714  " }
@@ -232,7 +237,8 @@ body.shift .highlight {
 
 .wilderness, .cultivated, .box, .militia-box, .leader-box {
 	position: absolute;
-	border: 5px solid transparent;
+	box-sizing: border-box;
+	border: 4px solid transparent;
 }
 .wilderness {
 	border-radius: 50%;
@@ -244,50 +250,85 @@ body.shift .highlight {
 	background-size: cover;
 	background-repeat: no-repeat;
 }
-.mountain.tip {
-	background-image: url(mountain-tip.svg);
-	z-index: 100;
-}
 .mountain.highlight {
 	background-image: url(mountain-highlight.svg);
+	filter: drop-shadow(0 0 2px black);
+}
+.mountain.danger {
+	background-image: url(mountain-danger.svg);
+	filter: drop-shadow(0 0 2px black);
 }
 .mountain.selected {
 	background-image: url(mountain-selected.svg);
+	filter: drop-shadow(0 0 2px black);
 }
 .mountain.british_supply {
 	background-image: url(mountain-supply-british.svg);
+	filter: none;
 }
 .mountain.french_supply {
 	background-image: url(mountain-supply-french.svg);
+	filter: none;
 }
 .mountain.british_supply.french_supply {
 	background-image: url(mountain-supply-both.svg);
+	filter: none;
+}
+.mountain.no_supply {
+	background-image: none;
+}
+.mountain.tip {
+	background-image: url(mountain-tip.svg);
+	z-index: 100;
 }
 
-.cultivated.highlight, .box.highlight, .militia-box.highlight {
-	border-color: white;
-	box-shadow: 0 0 5px white;
+.wilderness.highlight, .cultivated.highlight, .box.highlight, .militia-box.highlight {
+	border-color: yellow;
+	box-shadow: inset 0 0 3px black, 0 0 3px black;
 }
-.wilderness.highlight {
+.wilderness.selected, .cultivated.selected, .box.selected, .militia-box.selected {
 	border-color: white;
+	box-shadow: inset 0 0 3px black, 0 0 3px black;
 }
-.wilderness.selected, .cultivated.selected, .box.selected, .militia-box.selected {
-	border-color: crimson;
+.wilderness.danger, .cultivated.danger, .box.danger {
+	box-shadow: inset 0 0 0 3px red, inset 0 0 3px 3px black, 0 0 3px black;
 }
 .wilderness.tip, .cultivated.tip, .box.tip, .militia-box.tip {
-	border-color: yellow;
-	border-style: dashed;
+	border-color: white;
+	box-shadow: 0 0 3px black, inset 0 0 3px black;
 	z-index: 100;
 }
 
 .wilderness.french_supply, .cultivated.french_supply, .box.french_supply {
-	border-top-color: #0092d5;
-	border-left-color: #0092d5;
+	border-width: 6px;
+	border-top-color: blue;
+	border-left-color: blue;
+	border-bottom-color: transparent;
+	border-right-color: transparent;
+	box-shadow: none;
 }
 
 .wilderness.british_supply, .cultivated.british_supply, .box.british_supply {
-	border-bottom-color: #f0594e;
-	border-right-color: #f0594e;
+	border-width: 6px;
+	border-top-color: transparent;
+	border-left-color: transparent;
+	border-bottom-color: red;
+	border-right-color: red;
+	box-shadow: none;
+}
+
+.wilderness.british_supply.french_supply, .cultivated.british_supply.french_supply, .box.british_supply.french_supply {
+	border-width: 6px;
+	border-top-color: blue;
+	border-left-color: blue;
+	border-bottom-color: red;
+	border-right-color: red;
+	box-shadow: none;
+}
+
+.wilderness.no_supply, .cultivated.no_supply, .box.no_supply {
+	border-color: transparent;
+	box-shadow: none;
 }
 
 /* COUNTERS */
@@ -319,12 +360,13 @@ body.flat .event {
 
 body.flat .leader.highlight,
 body.flat .unit.highlight {
-	box-shadow:0 0 0 2px yellow;
+	box-shadow: 0 0 0 3px var(--highlight-color);
 }
 
 body.flat .leader.selected,
 body.flat .unit.selected {
-	box-shadow:0 0 0 2px crimson;
+	box-shadow: 0 0 0 3px var(--selected-color);
+	border-color: var(--selected-color) !important;
 }
 
 /* BEVEL STYLE ( top right bottom left ) */
@@ -492,120 +534,84 @@ body.bevel .event {
 
 .leader{background-color:#f0f0f0}
 body.bevel .leader{border-color:#f5f5f5 #d8d8d8 #d8d8d8 #f5f5f5;box-shadow:0 0 0 1px #707070}
-body.bevel .leader.highlight{box-shadow:0 0 0 1px #707070,0 0 0 3px yellow}
-body.bevel .leader.selected{box-shadow:0 0 0 1px #707070,0 0 0 3px crimson}
 body.flat .leader{border-color:#707070}
 .event{background-color:#f0f0f0}
 body.bevel .event{border-color:#f5f5f5 #d8d8d8 #d8d8d8 #f5f5f5;box-shadow:0 0 0 1px #707070}
-body.bevel .event.highlight{box-shadow:0 0 0 1px #707070,0 0 0 3px yellow}
-body.bevel .event.selected{box-shadow:0 0 0 1px #707070,0 0 0 3px crimson}
 body.flat .event{border-color:#707070}
 .marker.amphib{background-color:#f0f0f0}
 body.bevel .marker.amphib{border-color:#f5f5f5 #d8d8d8 #d8d8d8 #f5f5f5;box-shadow:0 0 0 1px #707070}
-body.bevel .marker.amphib.highlight{box-shadow:0 0 0 1px #707070,0 0 0 3px yellow}
-body.bevel .marker.amphib.selected{box-shadow:0 0 0 1px #707070,0 0 0 3px crimson}
 body.flat .marker.amphib{border-color:#707070}
 .marker.british_allied{background-color:#ffd990}
 body.bevel .marker.british_allied{border-color:#fff8af #dfb86f #dfb86f #fff8af;box-shadow:0 0 0 1px #7f580f}
-body.bevel .marker.british_allied.highlight{box-shadow:0 0 0 1px #7f580f,0 0 0 3px yellow}
-body.bevel .marker.british_allied.selected{box-shadow:0 0 0 1px #7f580f,0 0 0 3px crimson}
 body.flat .marker.british_allied{border-color:#7f580f}
 .marker.french_allied{background-color:#ffd990}
 body.bevel .marker.french_allied{border-color:#fff8af #dfb86f #dfb86f #fff8af;box-shadow:0 0 0 1px #7f580f}
-body.bevel .marker.french_allied.highlight{box-shadow:0 0 0 1px #7f580f,0 0 0 3px yellow}
-body.bevel .marker.french_allied.selected{box-shadow:0 0 0 1px #7f580f,0 0 0 3px crimson}
 body.flat .marker.french_allied{border-color:#7f580f}
 .marker.british_stockade{background-color:#e7e2c5}
 body.bevel .marker.british_stockade{border-color:#ffffe3 #c7c2a4 #c7c2a4 #ffffe3;box-shadow:0 0 0 1px #676244}
-body.bevel .marker.british_stockade.highlight{box-shadow:0 0 0 1px #676244,0 0 0 3px yellow}
-body.bevel .marker.british_stockade.selected{box-shadow:0 0 0 1px #676244,0 0 0 3px crimson}
 body.flat .marker.british_stockade{border-color:#676244}
 .marker.french_stockade{background-color:#e7e2c5}
 body.bevel .marker.french_stockade{border-color:#ffffe3 #c7c2a4 #c7c2a4 #ffffe3;box-shadow:0 0 0 1px #676244}
-body.bevel .marker.french_stockade.highlight{box-shadow:0 0 0 1px #676244,0 0 0 3px yellow}
-body.bevel .marker.french_stockade.selected{box-shadow:0 0 0 1px #676244,0 0 0 3px crimson}
 body.flat .marker.french_stockade{border-color:#676244}
 .marker.british_raided{background-color:#f78b33}
 body.bevel .marker.british_raided{border-color:#ffaa52 #d76a12 #d76a12 #ffaa52;box-shadow:0 0 0 1px #770a00}
-body.bevel .marker.british_raided.highlight{box-shadow:0 0 0 1px #770a00,0 0 0 3px yellow}
-body.bevel .marker.british_raided.selected{box-shadow:0 0 0 1px #770a00,0 0 0 3px crimson}
 body.flat .marker.british_raided{border-color:#770a00}
 .marker.french_raided{background-color:#f78b33}
 body.bevel .marker.french_raided{border-color:#ffaa52 #d76a12 #d76a12 #ffaa52;box-shadow:0 0 0 1px #770a00}
-body.bevel .marker.french_raided.highlight{box-shadow:0 0 0 1px #770a00,0 0 0 3px yellow}
-body.bevel .marker.french_raided.selected{box-shadow:0 0 0 1px #770a00,0 0 0 3px crimson}
 body.flat .marker.french_raided{border-color:#770a00}
 .marker.siege_0{background-color:#fff460}
 body.bevel .marker.siege_0{border-color:#ffff78 #dfd43f #dfd43f #ffff78;box-shadow:0 0 0 1px #7f7400}
-body.bevel .marker.siege_0.highlight{box-shadow:0 0 0 1px #7f7400,0 0 0 3px yellow}
-body.bevel .marker.siege_0.selected{box-shadow:0 0 0 1px #7f7400,0 0 0 3px crimson}
 body.flat .marker.siege_0{border-color:#7f7400}
 .marker.siege_1{background-color:#fff460}
 body.bevel .marker.siege_1{border-color:#ffff78 #dfd43f #dfd43f #ffff78;box-shadow:0 0 0 1px #7f7400}
-body.bevel .marker.siege_1.highlight{box-shadow:0 0 0 1px #7f7400,0 0 0 3px yellow}
-body.bevel .marker.siege_1.selected{box-shadow:0 0 0 1px #7f7400,0 0 0 3px crimson}
 body.flat .marker.siege_1{border-color:#7f7400}
 .marker.siege_2{background-color:#fff460}
 body.bevel .marker.siege_2{border-color:#ffff78 #dfd43f #dfd43f #ffff78;box-shadow:0 0 0 1px #7f7400}
-body.bevel .marker.siege_2.highlight{box-shadow:0 0 0 1px #7f7400,0 0 0 3px yellow}
-body.bevel .marker.siege_2.selected{box-shadow:0 0 0 1px #7f7400,0 0 0 3px crimson}
 body.flat .marker.siege_2{border-color:#7f7400}
 .marker.fieldworks{background-color:#e3dfd6}
 body.bevel .marker.fieldworks{border-color:#fffef5 #c3beb5 #c3beb5 #fffef5;box-shadow:0 0 0 1px #635e55}
-body.bevel .marker.fieldworks.highlight{box-shadow:0 0 0 1px #635e55,0 0 0 3px yellow}
-body.bevel .marker.fieldworks.selected{box-shadow:0 0 0 1px #635e55,0 0 0 3px crimson}
 body.flat .marker.fieldworks{border-color:#635e55}
 .unit.british{background-color:#eac99e}
 body.bevel .unit.british{border-color:#ffe8bd #caa87d #caa87d #ffe8bd;box-shadow:0 0 0 1px #6a481d}
-body.bevel .unit.british.highlight{box-shadow:0 0 0 1px #6a481d,0 0 0 3px yellow}
-body.bevel .unit.british.selected{box-shadow:0 0 0 1px #6a481d,0 0 0 3px crimson}
 body.flat .unit.british{border-color:#6a481d}
 .marker.british_fort{background-color:#ef473e}
 body.bevel .marker.british_fort{border-color:#ff665d #cf261d #cf261d #ff665d;box-shadow:0 0 0 1px #770000}
-body.bevel .marker.british_fort.highlight{box-shadow:0 0 0 1px #770000,0 0 0 3px yellow}
-body.bevel .marker.british_fort.selected{box-shadow:0 0 0 1px #770000,0 0 0 3px crimson}
 body.flat .marker.british_fort{border-color:#770000}
 .marker.british_fort_uc{background-color:#f15a4f}
 body.bevel .marker.british_fort_uc{border-color:#ff796e #d1392e #d1392e #ff796e;box-shadow:0 0 0 1px #710000}
-body.bevel .marker.british_fort_uc.highlight{box-shadow:0 0 0 1px #710000,0 0 0 3px yellow}
-body.bevel .marker.british_fort_uc.selected{box-shadow:0 0 0 1px #710000,0 0 0 3px crimson}
 body.flat .marker.british_fort_uc{border-color:#710000}
 .unit.french{background-color:#aae0fa}
 body.bevel .unit.french{border-color:#c9ffff #89c0da #89c0da #c9ffff;box-shadow:0 0 0 1px #29607a}
-body.bevel .unit.french.highlight{box-shadow:0 0 0 1px #29607a,0 0 0 3px yellow}
-body.bevel .unit.french.selected{box-shadow:0 0 0 1px #29607a,0 0 0 3px crimson}
 body.flat .unit.french{border-color:#29607a}
 .marker.french_fort{background-color:#007ec5}
 body.bevel .marker.french_fort{border-color:#1f9ee5 #005ea5 #005ea5 #1f9ee5;box-shadow:0 0 0 1px #001d64}
-body.bevel .marker.french_fort.highlight{box-shadow:0 0 0 1px #001d64,0 0 0 3px yellow}
-body.bevel .marker.french_fort.selected{box-shadow:0 0 0 1px #001d64,0 0 0 3px crimson}
 body.flat .marker.french_fort{border-color:#001d64}
 .marker.french_fort_uc{background-color:#0093d6}
 body.bevel .marker.french_fort_uc{border-color:#1fb3f6 #0073b6 #0073b6 #1fb3f6;box-shadow:0 0 0 1px #002467}
-body.bevel .marker.french_fort_uc.highlight{box-shadow:0 0 0 1px #002467,0 0 0 3px yellow}
-body.bevel .marker.french_fort_uc.selected{box-shadow:0 0 0 1px #002467,0 0 0 3px crimson}
 body.flat .marker.french_fort_uc{border-color:#002467}
 .marker.season_french_first{background-color:#0072bb}
 body.bevel .marker.season_french_first{border-color:#1f92db #00529b #00529b #1f92db;box-shadow:0 0 0 1px #001963}
-body.bevel .marker.season_french_first.highlight{box-shadow:0 0 0 1px #001963,0 0 0 3px yellow}
-body.bevel .marker.season_french_first.selected{box-shadow:0 0 0 1px #001963,0 0 0 3px crimson}
 body.flat .marker.season_french_first{border-color:#001963}
 .marker.season_british_first{background-color:#da2127}
 body.bevel .marker.season_british_first{border-color:#fa4046 #ba0006 #ba0006 #fa4046;box-shadow:0 0 0 1px #810000}
-body.bevel .marker.season_british_first.highlight{box-shadow:0 0 0 1px #810000,0 0 0 3px yellow}
-body.bevel .marker.season_british_first.selected{box-shadow:0 0 0 1px #810000,0 0 0 3px crimson}
 body.flat .marker.season_british_first{border-color:#810000}
 .marker.provincial_assemblies{background-color:#004892}
 body.bevel .marker.provincial_assemblies{border-color:#1f68b2 #002872 #002872 #1f68b2;box-shadow:0 0 0 1px #000d57}
-body.bevel .marker.provincial_assemblies.highlight{box-shadow:0 0 0 1px #000d57,0 0 0 3px yellow}
-body.bevel .marker.provincial_assemblies.selected{box-shadow:0 0 0 1px #000d57,0 0 0 3px crimson}
 body.flat .marker.provincial_assemblies{border-color:#000d57}
 .marker.vps{background-color:#b4883d}
 body.bevel .marker.vps{border-color:#d4a75c #94671c #94671c #d4a75c;box-shadow:0 0 0 1px #340700}
-body.bevel .marker.vps.highlight{box-shadow:0 0 0 1px #340700,0 0 0 3px yellow}
-body.bevel .marker.vps.selected{box-shadow:0 0 0 1px #340700,0 0 0 3px crimson}
 body.flat .marker.vps{border-color:#340700}
 
+/* action highlight */
+body.bevel .leader.highlight{box-shadow:0 0 0 1px #707070,0 0 0 4px var(--highlight-color)}
+body.bevel .unit.british.highlight{box-shadow:0 0 0 1px #6a481d,0 0 0 4px var(--highlight-color)}
+body.bevel .unit.french.highlight{box-shadow:0 0 0 1px #29607a,0 0 0 4px var(--highlight-color)}
+
+/* selected */
+body.bevel .leader.selected{box-shadow:0 0 0 3px var(--selected-color)}
+body.bevel .unit.british.selected{box-shadow:0 0 0 3px var(--selected-color)}
+body.bevel .unit.french.selected{box-shadow:0 0 0 3px var(--selected-color)}
+
 /* MOBILE PHONE LAYOUT */
 
 @media (max-width: 640px) {
diff --git a/play.js b/play.js
index 920b31e..ca342df 100644
--- a/play.js
+++ b/play.js
@@ -138,6 +138,7 @@ function show_supply(supply) {
 	for (let s = 1; s <= last_space; ++s) {
 		spaces[s].element.classList.toggle("french_supply", supply.french.includes(s))
 		spaces[s].element.classList.toggle("british_supply", supply.british.includes(s))
+		spaces[s].element.classList.toggle("no_supply", !supply.british.includes(s) && !supply.french.includes(s))
 	}
 }
 
@@ -147,6 +148,7 @@ function hide_supply() {
 		for (let s = 1; s <= last_space; ++s) {
 			spaces[s].element.classList.remove("french_supply")
 			spaces[s].element.classList.remove("british_supply")
+			spaces[s].element.classList.remove("no_supply")
 		}
 	}
 }
@@ -884,17 +886,16 @@ function destroy_faction_marker(space_id, faction, what) {
 
 function build_space(id) {
 	let space = spaces[id]
+
 	/* Make space for border */
 	let x = space.x
 	let y = space.y
 	let w = space.w
 	let h = space.h
 
-	if (space.type === 'box') { x -= 1; y -= 1; w -= 9; h -= 9; }
-	if (space.type === 'militia-box') { x -= 1; y -= 1; w -= 9; h -= 9; }
-	if (space.type === 'cultivated') { x -= 1; y -= 1; w -= 9; h -= 9; }
-	if (space.type === 'wilderness') { x -= 1; y -= 1; w -= 9; h -= 9; }
-	if (space.type === 'leader-box') { x -= 1; y -= 1; w -= 9; h -= 9; }
+	if (space.type !== 'mountain') {
+		x -= 1; y -= 1; w += 2; h += 2;
+	}
 
 	space.fstack = []
 	space.fstack.name = spaces[id].name + "/french"
@@ -1014,17 +1015,17 @@ function is_different_piece(a, b) {
 const style_dims = {
 	flat: {
 		width: 47,
-		gap: 2,
+		gap: 3,
 		thresh: [ 24, 16, 10,  8,  6,  0 ],
 		offset: [  1,  2,  3,  4,  5,  6 ],
-		focus_margin: 5,
+		focus_margin: 6,
 	},
 	bevel: {
 		width: 49,
-		gap: 4,
+		gap: 5,
 		thresh: [ 24, 16, 10,  8,  6,  0 ],
 		offset: [  1,  2,  3,  4,  5,  6 ],
-		focus_margin: 6,
+		focus_margin: 7,
 	},
 }
 
@@ -1049,7 +1050,7 @@ function layout_stack(stack, x, y, dx) {
 	if (stack === focus && is_small_stack(stack))
 		focus = null
 
-	if (stack === focus) {
+	if (stack === focus && layout < 2) {
 		let w, h
 		if (layout === 0) {
 			h = (dim.width + dim.gap) * (n-1)
@@ -1304,6 +1305,11 @@ function update_space(s) {
 	else
 		space.element.classList.remove("highlight")
 
+	if (view.danger && view.danger.includes(s))
+		space.element.classList.add("danger")
+	else
+		space.element.classList.remove("danger")
+
 	if (view.where === s)
 		space.element.classList.add("selected")
 	else
diff --git a/rules.js b/rules.js
index 575a055..fbb1b0e 100644
--- a/rules.js
+++ b/rules.js
@@ -1,5 +1,7 @@
 "use strict"
 
+// TODO: "danger_space" action for moving into interception/battle
+
 // WONTFIX
 // TODO: select leader for defense instead of automatically picking the best
 // TODO: remove old 7 command leader(s) immediately as they're drawn, before placing reinforcements
@@ -2961,6 +2963,40 @@ function has_friendly_fortifications_or_cultivated(s) {
 	return has_friendly_fortifications(s) || is_originally_friendly(s)
 }
 
+function add_danger_space(s) {
+	if (!view.danger)
+		view.danger = []
+	set_add(view.danger, s)
+}
+
+// Check if this move may lead to intercept/battle/other loss of control that prevents undo
+function is_danger_move(from, to) {
+	// Lake Schooner
+	if (is_enemy_card_available(LAKE_SCHOONER))
+		if (has_enemy_fortifications(to) && is_lake_connection(from, to))
+			return true
+
+	// Battle (and interception if infiltrating)
+	if (has_unbesieged_enemy_units(to))
+		return true
+
+	// Retreat Lone Leader
+	if (has_unbesieged_enemy_leader(to))
+		return true
+
+	// Interception
+	if (can_be_intercepted(from, to))
+		return true
+
+	return false
+}
+
+function gen_action_move(from, to) {
+	if (is_danger_move(from, to))
+		add_danger_space(to)
+	gen_action_space(to)
+}
+
 function gen_naval_move() {
 	let from = moving_piece_space()
 	if (!piece_can_naval_move_from(moving_piece(), from))
@@ -2968,19 +3004,19 @@ function gen_naval_move() {
 	if (game.active === BRITAIN) {
 		game.amphib.forEach(to => {
 			if (to !== from)
-				gen_action_space(to)
+				gen_action_move(from, to)
 		})
 		ports.forEach(to => {
 			if (to !== from && !set_has(game.amphib, to))
 				if (is_friendly_controlled_space(to))
-					gen_action_space(to)
+					gen_action_move(from, to)
 		})
 	}
 	if (game.active === FRANCE) {
 		if (from !== LOUISBOURG && is_friendly_controlled_space(LOUISBOURG))
-			gen_action_space(LOUISBOURG)
+			gen_action_move(from, LOUISBOURG)
 		if (from !== QUEBEC && is_friendly_controlled_space(QUEBEC))
-			gen_action_space(QUEBEC)
+			gen_action_move(from, QUEBEC)
 	}
 }
 
@@ -3110,14 +3146,14 @@ function gen_regular_move() {
 		switch (game.move.type) {
 		case 'boat-or-land':
 			if (can_move_by_boat_or_land(game.move.used, game.move.did_carry, from, to))
-				gen_action_space(to)
+				gen_action_move(from, to)
 			break
 		case 'boat':
 			if (can_move_by_boat(game.move.used, game.move.did_carry, from, to))
-				gen_action_space(to)
+				gen_action_move(from, to)
 			break
 		case 'land':
-			gen_action_space(to)
+			gen_action_move(from, to)
 			break
 		}
 	})
@@ -3572,12 +3608,12 @@ states.amphibious_landing = {
 		view.prompt = `Amphibious Landing: Select a destination for ${piece_name_and_place(who)}.`
 		view.who = who
 		if (from === HALIFAX) {
-			gen_action_space(LOUISBOURG)
+			gen_action_move(from, LOUISBOURG)
 		}
 		if (from === LOUISBOURG) {
-			gen_action_space(BAIE_ST_PAUL)
-			gen_action_space(RIVIERE_OUELLE)
-			gen_action_space(ILE_D_ORLEANS)
+			gen_action_move(from, BAIE_ST_PAUL)
+			gen_action_move(from, RIVIERE_OUELLE)
+			gen_action_move(from, ILE_D_ORLEANS)
 		}
 	},
 	space(to) {
@@ -3676,12 +3712,10 @@ function end_move() {
 
 // INTERCEPT
 
-function can_be_intercepted() {
+function can_be_intercepted(came_from, here) {
 	let result = false
 
 	let who = moving_piece()
-	let here = moving_piece_space()
-	let came_from = moving_piece_came_from()
 
 	// 6.723 Leaders moving alone can NOT be intercepted
 	if (is_lone_leader(who))
@@ -3779,7 +3813,7 @@ function goto_intercept() {
 		}
 	}
 
-	if (can_be_intercepted()) {
+	if (can_be_intercepted(moving_piece_came_from(), moving_piece_space())) {
 		game.move.intercepting = 0
 		set_active_enemy()
 		game.state = 'intercept_who'