# Homeworlds - Monopoly

Lee wins in 5 turns (click the image for a bigger version)

This puzzle is inspired by the other Homeworlds puzzles introduced by @Destructible Lemon. You should explain how Lee (the player on the left side) can beat Ray (the player on the right side) in 5 turns. Ray will of course try to prevent this if he can.

Text version:

System name     Stars    Lees ships     Rays ships

Lee             Y1B2     Y2Y1B2B1
DS1             B2       Y3Y1B1
DS2             Y2       Y3Y2B3B1
DS3             G2                      G1
DS4             R2                      R2G3
DS5             G2                      G1
DS6             R3                      R1G3
DS7             R2                      R1G3
Ray             R1                      R3


I have uploaded an Inkscape template in case you would like to create similar puzzles yourself. The background for the puzzle is from here.

• btw it tends to be standard to arrange the systems, when there are more than one non-homeworld system, so that near the homeworlds are systems they can move to with both their homeworlds blocking movement. Also minor nitpick: that is a very cyany blue. Otherwise, good job on making a puzzle with a decent number of moves – Destructible Lemon Nov 18 '17 at 22:23
• I had to fix the puzzle to make sure there aren't unwanted solutions. This invalidates the current answer, so please DON'T downvote the answer. – Sleafar Nov 19 '17 at 8:24

sorry it took so long. :p

i made a diagram, which has moves which don't need specific spaces (i think?) have specific spaces.

(the yellow blue ship is because it doesn't matter which of blue or yellow is captured and either could be but like i guess i didn't need to do that)

turn 1: transmute a large to red (ray builds a small green)
turn 2: transmute a medium to green (ray sacrifices and builds a small green)
turn 3: sacrifice medium green, build two larges (careful not to catastrophe anything) (ray builds medium green)
turn 4: sacrifice a yellow large, move 3 nonred larges to rays homeworld, ray sacrifices medium red to capture 2 of these larges
turn 5: sacrifice red large to capture all of rays ships at his homeworld, winning.

Turn 1: sacrifice yellow large at homeworld, move blue large and yellow large (remaining one) to DS4 and DS3 respectively. also move a yellow small to DS3

if ray chooses to catastrophise either of DS4 and DS3, we will be able to change some of our pieces to reds next turn, and explode his homeworld on turn 3. if he does not do something, we are able to catastrophise with our large blue changing the large yellow to green or red, and using the remaining two changes to change some pieces on DS 1 and 2 to red before exploding the homeworld on turn 3. in fact, if he does not get rid of the large red, something will be catastrophised. so he builds it on his homeworld, by sacrificing a green on DS3 (small) to build, so it cannot be catastrophised in one turn.

turn 2: we would like to attack and capture a red, but Ray would just capture back. we will instead sacrifice a blue large to change the two yellows to greens, and catastrophise the system. we now have 3 reds in the bank. use the remaining change to swap a the small in DS1 to a red.

Ray's response. Ray currently can't do anything except sacrifice pieces for no goal, or catastophise something. the best such one would be sacrificing a red at his homeworld

Turn 3: swap the medium yellow at DS2 to a red.

Ray's response. he has none. he can't build to help himself, a catastrophe at this point is pointless for him.

turn 4 sacrifice a yellow medium to move both the reds at Ray's homeworld, regardless of his last move. catastrophise.

What'd I miss? how come it worked so quickly? oh wait i know. he could have sacrificed his medium and... nope, that doesn't save him. capturing the yellow allows the system to be catastrophed the next turn, and setup to ray losing next turn. Oh i see... I think it's because he could've prevented the use of the smalls by... wait nvm if he kept a small with him to prevent it from being built, it would have been a liability in the end anyway. actually, it might have slowed Lee down... let me see...

Turn 1: sacrifice yellow large at homeworld, move blue large and yellow large (remaining one) to DS4 and DS3 respectively. also move a yellow small to DS3

Ray responds by sacrificing a green 2 in DS3, building red in DS3, overpopulation, and building the red small at his homeworld

turn 2: sacrifice medium blue, catastrophe DS4, change small blue to red.

ray: can't do anything but remove a red, or build a green, or steal a yellow. stealing yellow means instant loss (red catastrophe).

turn 3: change something else to red: yellow at DS2. ray: build or nothing. either way he's doomed

turn 4: move red pieces to Ray's homeworld, catastrophe, win.

still not five...

please point out what i did wrong?

Monopoly is because both players have a monopoly on at least one colour at at least one point in the game (Ray monopolises red).

• The problem is, I messed up. Do you mind if I try to fix it, if possible? – Sleafar Nov 19 '17 at 5:06
• you may. @Sleafar – Destructible Lemon Nov 19 '17 at 7:09
• I have updated the puzzle. It took quite a while to make sure there aren't any unwanted solutions left. Hopefully I didn't overlook something again, there are way too many possibilities with that many ships. – Sleafar Nov 19 '17 at 8:22
• Will you try to solve this? – Sleafar Nov 20 '17 at 20:42
• @Sleafar some time, yes. – Destructible Lemon Nov 20 '17 at 22:15