Magic is reliable, magic is hard to cheat, and magic is a more convenient tool to safeguard riches or secrets then intelligent creatures, or monsters of any kind. Arcane sentinels are abjuration-specialist wizards who focus on magic that wards areas and prevents intrusion. Their spells are more durable, harder to remove, and more deadly when properly placed. Master Bertio Ranberd is the most renowned practitioner of the arcane sentinel school in Aglarion, teaching his secret formulas at his shop and boarding school, the Emporium of Marvelous Rarities.

Practiced Abjurer

Practiced Abjurer. Starting at 2nd level, you become practiced at learning abjuration spells. The gold and time you must spend to copy an abjuration spell into your spellbook is halved.

Advanced Alarm

Advanced Alarm. Starting at 2nd level, you gain deeper insight into the working of the alarm spell. The duration of an alarm spell cast by you becomes 24 hours and it is both mental and audible. You can also designate other willing creatures to be alerted by your alarm spell’s mental alert. 

Empowered Glyph

Empowered Glyph. Starting at 6th level, you can inscribe the glyph of warding spell in an instant and make it more potent. You can cast the glyph of warding spell as an action and reroll a number of the damage dice equal to your Intelligence modifier (minimum 1) when using the spell’s explosive runes option. You must use the new rolls. Once you use this feature, you can’t use it until you finish a long rest. 

Tenacious Abjurations

Tenacious Abjurations. Starting at 10th level, your abjuration spells become hard to dispel. An attempt to dispel your 3rd or lower level abjuration spells require an ability check. All ability checks made to dispel an abjuration spell cast by you have disadvantage.

Logical Defence

Logical Defence. Starting at 14th level, you can deduct the outcome of a threat directed at you. As a reaction, you can add your Intelligence modifier (minimum 1) as a bonus to your AC or a saving throw made against a spell.