diff --git a/src/expansion.cr b/src/expansion.cr
index 11a997a..7874078 100644
--- a/src/expansion.cr
+++ b/src/expansion.cr
@@ -7,7 +7,7 @@ world = Game::World.new(ts)
 
 router = CLI::CommandRouter.new
 
-router.add "harv {x} {y}", "Build harvester at x,y" do |p|
+router.add "harv {x} {y}", "Build harvester at x,y (+80cr/10s)" do |p|
   x = p["x"].to_i32
   y = p["y"].to_i32
   point = Game::Point.new(x, y)
@@ -15,14 +15,14 @@ router.add "harv {x} {y}", "Build harvester at x,y" do |p|
   printf "Build harvester at %d %d\n", x, y
 end
 
-router.add "rest {x} {y}", "Build restorer at x,y (100 cr)" do |p|
+router.add "rest {x} {y}", "Build restorer at x,y (100 cr, +30cr/15s)" do |p|
   x = p["x"].to_i32
   y = p["y"].to_i32
   point = Game::Point.new(x, y)
   world.push(Game::BuildCrystalRestorerCommand.new(point))
 end
 
-router.add "terr {x} {y}", "Build terraformator at x,y (300 cr)" do |p|
+router.add "terr {x} {y}", "Build terraformator at x,y (300 cr, +5terr/-50cr/60s)" do |p|
   x = p["x"].to_i32
   y = p["y"].to_i32
   point = Game::Point.new(x, y)
diff --git a/src/game/command.cr b/src/game/command.cr
index e72631b..2ed6327 100644
--- a/src/game/command.cr
+++ b/src/game/command.cr
@@ -170,13 +170,22 @@ module Game
 
   class TerraformCommand < Command
     PRODUCTION_TIME  = 60
+    REST_TIME        = 20
     PRODUCTION_VALUE =  5
+    CRYSTAL_REQUIRED = 50
 
     def initialize(@point : Point)
+      @can_terr = false
     end
 
     def start(world : World) : Int32
-      PRODUCTION_TIME
+      if world.resources.has(ResourceType::Crystal, CRYSTAL_REQUIRED)
+        world.resources.dec(ResourceType::Crystal, CRYSTAL_REQUIRED)
+        @can_terr = true
+        PRODUCTION_TIME
+      else
+        REST_TIME
+      end
     end
 
     def desc : String
@@ -184,7 +193,9 @@ module Game
     end
 
     def finish(world : World)
-      world.resources.inc(ResourceType::Terraformation, PRODUCTION_VALUE)
+      if @can_terr
+        world.resources.inc(ResourceType::Terraformation, PRODUCTION_VALUE)
+      end
       world.push(TerraformCommand.new(@point))
     end
   end
diff --git a/src/game/resources.cr b/src/game/resources.cr
index e1bcd08..1e1bcc5 100644
--- a/src/game/resources.cr
+++ b/src/game/resources.cr
@@ -17,6 +17,10 @@ class Game::Resources
     @values[t]
   end
 
+  def has(t : ResourceType, value : Int32) : Bool
+    @values[t] >= value
+  end
+
   def inc(t : ResourceType, value : Int32)
     new_value = @values[t] + value
     if new_value < 0