Two ivies climb the same house, but only one can reach the top. Leaves gather sunlight, and sunlight feeds growth. Once a turn you may choke any vine you touch. Anything cut off from its root belongs to nobody — and either ivy may graft it.
The house is nine columns, a to i, and twelve rows counting up from the soil. It narrows as it rises to a single cell at the top.
c6, c9, g6, g9, and the pair e2, e3 are glass. Nothing grows on glass, but it does not block sunlight.
a5 and i5 share an edge: the tunnel. A vine can creep through it from one wall of the house to the other.
Green roots at c1, Purple at g1. A root is always alive and can never be choked.
Green plays first and begins with 1 sun. Purple begins with 2, for moving second.
A cell is alive while an unbroken chain of vine cells, edge to edge, links it to a root. Only living cells may creep, leaf, gather sun, or choke.
A vine cut off from its root belongs to nobody and begins to wither. It stays where it is and keeps its leaves, but it shrinks every turn.
Grafting. The instant a withering branch shares an edge with a living cell, that ivy takes the whole branch immediately.
Your root draws 3 sun a turn. Everything else comes from your leaves, and only while they stand in the sunlight (lit) — nothing above them in their column except glass.
Leaves gather 1 sun in rows 2–4, 2 sun in rows 5–8, and 4 sun in rows 9–11.
Sun you don't use carries over.
Gather sun (Feed) from a leaf at the top, and you have won.
Creep — 1 sun for each of your cells beside it. Grow into an empty cell sharing an edge with your living vine — never diagonally; the tunnel counts as an edge. A creep costs 1 to 4 sun, one for each edge it shares with your vine.
Leaf — 1 sun, plus 1 for every lit leaf you own. Put out a leaf on a living cell you own. One per cell, never in the soil. With none lit, a leaf costs 1; with two lit, it costs 3. Shaded leaves don't count.
Choke — free. Kill any vine cell sharing an edge with a living cell of yours — never a root. It becomes deadwood marked 2 — gone after two turns, this one included. Deadwood belongs to nobody and blocks both sunlight and growth.
Feed. Take the sun your root and your lit leaves gather.
Grow. Creep and leaf as much as you want, if you can afford it. Any order.
Choke. At most one.
Decay. Count every deadwood marker down by one and clear away any that reaches zero. Then each withering branch loses the highest cell that can go without splitting the branch in two, or the one nearest the middle column if two are level.