diff --git a/resource.digitalocean_droplet.this.tf b/resource.digitalocean_droplet.this.tf
index 9e9e635..e2ed016 100644
--- a/resource.digitalocean_droplet.this.tf
+++ b/resource.digitalocean_droplet.this.tf
@@ -1,18 +1,18 @@
 resource "digitalocean_droplet" "this" {
-  backups = true
+  backups = var.backups
   backup_policy {
     plan    = var.backup_policy_plan
     weekday = var.backup_policy_weekday
     hour    = var.backup_policy_hour
   }
   image = var.image_name
-  ipv6  = true
+  ipv6  = var.ipv6
   lifecycle {
     ignore_changes = [
       image,
     ]
   }
-  monitoring = true
+  monitoring = var.monitoring
   name       = "${var.host_name}.${var.domain_name}"
   region     = var.region
   ssh_keys   = var.ssh_keys
diff --git a/variable.backups.tf b/variable.backups.tf
new file mode 100644
index 0000000..a1a76b1
--- /dev/null
+++ b/variable.backups.tf
@@ -0,0 +1,5 @@
+variable "backups" {
+  default     = true
+  description = "Boolean controlling if backups are made"
+  type        = bool
+}
diff --git a/variable.domain_name.tf b/variable.domain_name.tf
index 67c98d8..246d5bc 100644
--- a/variable.domain_name.tf
+++ b/variable.domain_name.tf
@@ -1,6 +1,9 @@
 variable "domain_name" {
   description = "The domain name to use for the droplet's DNS record"
-  default     = "example.com"
   type        = string
-}
 
+  validation {
+    condition     = can(regex("^[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$", var.domain_name))
+    error_message = "The domain name must be a valid fully-qualified domain name (e.g., example.com)."
+  }
+}
diff --git a/variable.host_name.tf b/variable.host_name.tf
index 208425e..f1988c3 100644
--- a/variable.host_name.tf
+++ b/variable.host_name.tf
@@ -1,6 +1,9 @@
 variable "host_name" {
   description = "The hostname for the droplet"
-  default     = "hello-world"
   type        = string
-}
 
+  validation {
+    condition     = can(regex("^[a-zA-Z0-9-]+$", var.host_name))
+    error_message = "The host name can only contain alphanumeric characters and hyphens."
+  }
+}
diff --git a/variable.image_name.tf b/variable.image_name.tf
index 50857e4..3a7f6ac 100644
--- a/variable.image_name.tf
+++ b/variable.image_name.tf
@@ -1,6 +1,9 @@
 variable "image_name" {
   description = "The image ID or slug to use for the droplet"
-  default     = "fedora-42-x64"
   type        = string
-}
 
+  validation {
+    condition     = can(regex("^[a-zA-Z0-9-]+$", var.image_name))
+    error_message = "The image name must be a valid slug or ID."
+  }
+}
diff --git a/variable.ipv6.tf b/variable.ipv6.tf
new file mode 100644
index 0000000..818e0b2
--- /dev/null
+++ b/variable.ipv6.tf
@@ -0,0 +1,5 @@
+variable "ipv6" {
+  default     = true
+  description = "Boolean controlling if IPv6 is enabled"
+  type        = bool
+}
diff --git a/variable.monitoring.tf b/variable.monitoring.tf
new file mode 100644
index 0000000..32942a4
--- /dev/null
+++ b/variable.monitoring.tf
@@ -0,0 +1,5 @@
+variable "monitoring" {
+  default     = true
+  description = "Boolean controlling whether monitoring agent is installed"
+  type        = bool
+}
diff --git a/variable.region.tf b/variable.region.tf
index 95777ba..a1c8532 100644
--- a/variable.region.tf
+++ b/variable.region.tf
@@ -1,6 +1,9 @@
 variable "region" {
   description = "The region where the droplet will be created"
-  default     = "nyc3"
   type        = string
-}
 
+  validation {
+    condition     = can(regex("^[a-z]{3}[0-9]$", var.region))
+    error_message = "The region must be a valid DigitalOcean region format (e.g., nyc3, sfo3)."
+  }
+}
diff --git a/variable.size.tf b/variable.size.tf
index 480d289..e5c79a8 100644
--- a/variable.size.tf
+++ b/variable.size.tf
@@ -1,6 +1,9 @@
 variable "size" {
   description = "The slug indicating the size of the droplet"
-  default     = "s-1vcpu-1gb"
   type        = string
-}
 
+  validation {
+    condition     = can(regex("^[a-zA-Z0-9-]+$", var.size))
+    error_message = "The size must be a valid DigitalOcean size slug (e.g., s-1vcpu-1gb)."
+  }
+}
diff --git a/variable.tags.tf b/variable.tags.tf
index 3204e71..23995f3 100644
--- a/variable.tags.tf
+++ b/variable.tags.tf
@@ -1,6 +1,10 @@
 variable "tags" {
-  description = "A list of tags to apply to the droplet"
   default     = []
+  description = "A list of tags to apply to the droplet"
   type        = list(string)
-}
 
+  validation {
+    condition     = alltrue([for t in var.tags : can(regex("^[a-zA-Z0-9-_]+$", t))]) || length(var.tags) == 0
+    error_message = "Tags must only contain alphanumeric characters, hyphens, and underscores."
+  }
+}