diff --git a/internal/server/session.go b/internal/server/session.go
index 9234529..79603e3 100644
--- a/internal/server/session.go
+++ b/internal/server/session.go
@@ -98,6 +98,7 @@ func (sn *session) read() {
 					From: sn.Name,
 					Seq:  req.Seq,
 					Wants: &sim.SpawnPlayer{
+						Name:   sn.Name,
 						Outbox: sn.outbox,
 					},
 				}
diff --git a/internal/sim/effect.go b/internal/sim/effect.go
index fd4e5f8..7600a44 100644
--- a/internal/sim/effect.go
+++ b/internal/sim/effect.go
@@ -4,7 +4,7 @@ import "github.com/jordanorelli/astro-domu/internal/wire"
 
 type Effect interface {
 	wire.Value
-	exec(*room, string, int) result
+	exec(*room, *player, int) result
 }
 
 type result struct {
diff --git a/internal/sim/entity.go b/internal/sim/entity.go
index 4aaa1dc..d5c0138 100644
--- a/internal/sim/entity.go
+++ b/internal/sim/entity.go
@@ -1,11 +1,17 @@
 package sim
 
-import "time"
+import (
+	"time"
+)
 
-// entity is any entity that can be simulated.
-type entity interface {
-	id() int
+type Entity struct {
+	ID       int    `json:"id"`
+	Position [2]int `json:"pos"`
+	Glyph    rune   `json:"glyph"`
+	behavior
+}
 
+type behavior interface {
 	// update is the standard tick function
 	update(time.Duration)
 }
diff --git a/internal/sim/player.go b/internal/sim/player.go
index dace622..19bc859 100644
--- a/internal/sim/player.go
+++ b/internal/sim/player.go
@@ -1,65 +1,85 @@
 package sim
 
 import (
-	"time"
-
 	"github.com/jordanorelli/astro-domu/internal/wire"
 	"github.com/jordanorelli/blammo"
 )
 
-// player represents a player character in the simulation
+// player is a player session in the simulation, eek
 type player struct {
 	*blammo.Log
 	*room
-	name      string
-	outbox    chan wire.Response
-	sessionID int
-	entityID  int
-	pending   []Request
+	name    string
+	outbox  chan wire.Response
+	pending []Request
+	entity  *Entity
 }
 
-func (p *player) update(dt time.Duration) {}
-
-func (p *player) id() int { return p.entityID }
-
 type Move [2]int
 
 func (Move) NetTag() string { return "move" }
 
-func (m *Move) exec(r *room, from *player, seq int) {
-
+func (m *Move) exec(r *room, p *player, seq int) result {
+	pos := p.entity.Position
+	target := [2]int{pos[0] + m[0], pos[1] + m[1]}
+	p.Info("running move for player %s from %v to %v", p.name, *m, target)
+	if target[0] >= r.width || target[0] < 0 {
+		return result{reply: wire.Errorf("target cell (%d, %d) is out of bounds", target[0], target[1])}
+	}
+	if target[1] >= r.height || target[1] < 0 {
+		return result{reply: wire.Errorf("target cell (%d, %d) is out of bounds", target[0], target[1])}
+	}
+	n := target[1]*r.width + target[0]
+	if r.tiles[n].here != nil {
+		return result{reply: wire.Errorf("target cell (%d, %d) is occupied", target[0], target[1])}
+	}
+	p.entity.Position = target
+	return result{reply: wire.OK{}}
 }
 
+// type pawn struct {
+// }
+
 // SpawnPlayer is a request to spawn a player
 type SpawnPlayer struct {
 	Outbox chan wire.Response
+	Name   string
 	queued bool
 }
 
-func (s *SpawnPlayer) exec(r *room, from string, seq int) result {
+func (s *SpawnPlayer) exec(r *room, _ *player, seq int) result {
 	if !s.queued {
-		r.Info("spawn player requested for: %s", from)
+		r.Info("spawn player requested for: %s", s.Name)
 
-		if _, ok := r.players[from]; ok {
-			s.Outbox <- wire.ErrorResponse(seq, "a player is already logged in as %q", from)
+		if _, ok := r.players[s.Name]; ok {
+			s.Outbox <- wire.ErrorResponse(seq, "a player is already logged in as %q", s.Name)
 			return result{}
 		}
 
 		p := &player{
-			Log:     r.Log.Child("players").Child(from),
+			Log:     r.Log.Child("players").Child(s.Name),
 			room:    r,
-			name:    from,
+			name:    s.Name,
 			outbox:  s.Outbox,
 			pending: make([]Request, 0, 32),
+			entity: &Entity{
+				ID:       999,
+				Position: [2]int{0, 0},
+				Glyph:    '@',
+			},
 		}
-		p.pending = append(p.pending, Request{Seq: seq, From: from, Wants: s})
-		r.players[from] = p
+		p.pending = append(p.pending, Request{Seq: seq, From: s.Name, Wants: s})
+		r.players[s.Name] = p
 		s.queued = true
 		return result{}
 	}
 
 	return result{
-		reply: Welcome{Room: r.name},
+		reply: Welcome{
+			Room:     r.name,
+			Size:     [2]int{r.width, r.height},
+			Contents: r.allEntities(),
+		},
 	}
 }
 
@@ -67,16 +87,39 @@ func (SpawnPlayer) NetTag() string { return "player/spawn" }
 
 // PlayerSpawned is an announcement that a player has spawned
 type PlayerSpawned struct {
-	Name string
+	Name     string `json:"name"`
+	Position [2]int `json:"position"`
 }
 
+func (PlayerSpawned) NetTag() string { return "player/spawned" }
+
 type Welcome struct {
-	Room string `json:"room"`
+	Room     string   `json:"room"`
+	Size     [2]int   `json:"size"`
+	Contents []Entity `json:"contents"`
 }
 
+/*
+
+{
+	"name": "foyer",
+	"width": 10,
+	"height": 10,
+	"contents": [
+	  [5, 3, 10],
+	],
+	"entities": [
+	  [3, "pawn", {"name": "bones"}],
+	  [10, "pawn", {"name": "steve"}]
+	]
+}
+
+*/
+
 func (Welcome) NetTag() string { return "player/welcome" }
 
 func init() {
 	wire.Register(func() wire.Value { return new(Move) })
 	wire.Register(func() wire.Value { return new(Welcome) })
+	// wire.Register(func() wire.Value { return new(pawn) })
 }
diff --git a/internal/sim/room.go b/internal/sim/room.go
index 9f89a55..55582a5 100644
--- a/internal/sim/room.go
+++ b/internal/sim/room.go
@@ -18,21 +18,29 @@ type room struct {
 }
 
 func (r *room) update(dt time.Duration) {
-	// announcements := make([]result, 0, 8)
-
 	for _, p := range r.players {
 		for _, req := range p.pending {
-			res := req.Wants.exec(r, p.name, req.Seq)
+			res := req.Wants.exec(r, p, req.Seq)
 			p.outbox <- wire.Response{Re: req.Seq, Body: res.reply}
 		}
 		p.pending = p.pending[0:0]
 	}
 
 	for _, t := range r.tiles {
-		for _, e := range t.contents {
-			e.update(dt)
+		if t.here != nil {
+			t.here.update(dt)
+		}
+	}
+}
+
+func (r *room) allEntities() []Entity {
+	all := make([]Entity, 0, 4)
+	for _, t := range r.tiles {
+		if t.here != nil {
+			all = append(all, *t.here)
 		}
 	}
+	return all
 }
 
 func (r *room) addPlayer(p *player) {
diff --git a/internal/sim/tile.go b/internal/sim/tile.go
index 0a9bc37..6337cbe 100644
--- a/internal/sim/tile.go
+++ b/internal/sim/tile.go
@@ -1,30 +1,6 @@
 package sim
 
-// tile is an individual cell within the world simulation. Everything happens
-// on a tile.
 type tile struct {
-	// floor is the surface for the tile. All things sit atop the floor. The
-	// floor informs clients how to draw the tile in the event that the tile's
-	// contents are empty. The floor also determins whether or not the tile is
-	// traversable.
 	floor floor
-
-	// contents is all of the entities on this tile. A given tile may have many
-	// entities.
-	contents map[int]entity
-}
-
-func (t *tile) addEntity(e entity) {
-	if t.contents == nil {
-		t.contents = make(map[int]entity)
-	}
-	t.contents[e.id()] = e
-}
-
-func (t *tile) removeEntity(id int) entity {
-	if e, here := t.contents[id]; here {
-		delete(t.contents, id)
-		return e
-	}
-	return nil
+	here  *Entity
 }
diff --git a/internal/sim/world.go b/internal/sim/world.go
index 6657456..b7a1de2 100644
--- a/internal/sim/world.go
+++ b/internal/sim/world.go
@@ -60,7 +60,9 @@ func (w *World) Run(hz int) {
 					spawn.Outbox <- wire.ErrorResponse(req.Seq, "a player is already logged in as %q", req.From)
 					break
 				}
-				spawn.exec(&w.rooms[0], req.From, req.Seq)
+				spawn.exec(&w.rooms[0], nil, req.Seq)
+				p := w.rooms[0].players[req.From]
+				w.players[req.From] = p
 				break
 			}
 
@@ -68,7 +70,6 @@ func (w *World) Run(hz int) {
 			if !ok {
 				w.Error("received non login request of type %T from unknown player %q", req.Wants, req.From)
 			}
-			break
 
 			p.pending = append(p.pending, req)
 
diff --git a/internal/ui/mode.go b/internal/ui/mode.go
index dad9df8..34b4f84 100644
--- a/internal/ui/mode.go
+++ b/internal/ui/mode.go
@@ -10,13 +10,13 @@ type Mode interface {
 	draw(*UI)
 }
 
-type boxWalker struct {
+type roomDisplay struct {
 	width    int
 	height   int
 	position point
 }
 
-func (m *boxWalker) handleEvent(ui *UI, e tcell.Event) bool {
+func (m *roomDisplay) handleEvent(ui *UI, e tcell.Event) bool {
 	switch v := e.(type) {
 	case *tcell.EventKey:
 		key := v.Key()
@@ -24,16 +24,16 @@ func (m *boxWalker) handleEvent(ui *UI, e tcell.Event) bool {
 			switch v.Rune() {
 			case 'w':
 				ui.client.Send(sim.Move{0, -1})
-				m.move(0, -1)
+				// m.move(0, -1)
 			case 'a':
 				ui.client.Send(sim.Move{-1, 0})
-				m.move(-1, 0)
+				// m.move(-1, 0)
 			case 's':
 				ui.client.Send(sim.Move{0, 1})
-				m.move(0, 1)
+				// m.move(0, 1)
 			case 'd':
 				ui.client.Send(sim.Move{1, 0})
-				m.move(1, 0)
+				// m.move(1, 0)
 			}
 		}
 	default:
@@ -42,12 +42,12 @@ func (m *boxWalker) handleEvent(ui *UI, e tcell.Event) bool {
 	return true
 }
 
-func (m *boxWalker) move(dx, dy int) {
+func (m *roomDisplay) move(dx, dy int) {
 	m.position.x = clamp(m.position.x+dx, 0, m.width-1)
 	m.position.y = clamp(m.position.y+dy, 0, m.height-1)
 }
 
-func (m *boxWalker) draw(ui *UI) {
+func (m *roomDisplay) draw(ui *UI) {
 	offset := point{1, 1}
 
 	// fill in background dots first
@@ -72,5 +72,5 @@ func (m *boxWalker) draw(ui *UI) {
 	}
 
 	// add all characters
-	ui.screen.SetContent(m.position.x+offset.x, m.position.y+offset.y, '@', nil, tcell.StyleDefault)
+	// ui.screen.SetContent(m.position.x+offset.x, m.position.y+offset.y, '@', nil, tcell.StyleDefault)
 }
diff --git a/internal/ui/ui.go b/internal/ui/ui.go
index d2895b1..d5b3714 100644
--- a/internal/ui/ui.go
+++ b/internal/ui/ui.go
@@ -6,6 +6,7 @@ import (
 	"github.com/gdamore/tcell/v2"
 	"github.com/jordanorelli/astro-domu/internal/exit"
 	"github.com/jordanorelli/astro-domu/internal/server"
+	"github.com/jordanorelli/astro-domu/internal/sim"
 	"github.com/jordanorelli/astro-domu/internal/wire"
 	"github.com/jordanorelli/blammo"
 )
@@ -26,9 +27,23 @@ func (ui *UI) Run() {
 		return
 	}
 
-	ui.client.Send(server.Login{Name: ui.PlayerName})
+	res, err := ui.client.Send(server.Login{Name: ui.PlayerName})
+	if err != nil {
+		ui.Error("login error: %v", err)
+		return
+	}
 
-	ui.mode = &boxWalker{width: 10, height: 6}
+	welcome, ok := res.Body.(*sim.Welcome)
+	if !ok {
+		ui.Error("unexpected initial message of type %t", res.Body)
+		return
+	}
+	ui.Info("spawned into room %s", welcome.Room)
+
+	ui.mode = &roomDisplay{
+		width:  welcome.Size[0],
+		height: welcome.Size[1],
+	}
 	ui.Info("running ui")
 	if ui.handleUserInput() {
 		ui.Info("user requested close")
diff --git a/internal/wire/entity.go b/internal/wire/entity.go
new file mode 100644
index 0000000..4048932
--- /dev/null
+++ b/internal/wire/entity.go
@@ -0,0 +1 @@
+package wire